CLN3 disease, or Juvenile Neuronal Ceroid Lipofuscinosis (JNCL), is a rare, genetic neurodegenerative condition, typically manifesting in the first decade of life and progressing in severity, with death typically occurring in early adulthood. Despite two decades of natural history research, a clear timeline of CLN3 disease symptom onset and progression remains poorly defined, limiting optimal patient management and therapeutic development. We conducted a literature review and analysed the natural history data to better understand the age of core symptom onset and chronological disease progression. A literature review was undertaken using a pre-defined search strategy focused on CLN3 disease natural history studies, where age at onset for one or more core symptoms was reported in cohorts of ≥ 15 subjects. For each symptom, weighted mean age at onset and weighted standard deviation were calculated, with 95

Population-based evidence on cancer survival in individuals with neurofibromatosis 1 (NF1) remains limited. We compared survival following a first neoplasm in individuals with NF1 to that of the general Danish population and stratified on age, sex, and potential survival-related factors, including cancer stage and comorbidity. Using the Danish Cancer Registry, we identified 428 individuals with NF1 and 392,885 without NF1, all diagnosed with a first neoplasm (1977-2022). We estimated survival using Kaplan-Meier methods, assessed neoplastic and nonneoplastic mortality, and evaluated prior inpatient disease burden in adults (aged 20-69 years) based on hospital diagnoses 10 years to 6 months before neoplasm diagnosis. Among children (aged 1-19 years), NF1 was overall associated with better 5-year survival (NF1: 87.3% [81.1%-93.5%], non-NF1: 78.7% [77.9%-79.6%]), due to better survival following central nervous system (CNS) neoplasms. In adults, 5-year survival was lower in NF1 compared to the general population (57.0% [51.3%-62.6%] vs. 69.2% [69.0%-69.3%]). NF1 adults more often presented with stage IV breast (17.2% vs. 6.3%) and gastrointestinal cancers (52.5% vs. 37.7%). Among adults with no prior inpatient diagnoses, 5-year survival was poorer in NF1 (60.1% [51.3%-68.9%] vs. 72.1% [71.9%-72.3%]). Five-year neoplastic mortality was higher in NF1 adults (39.4% [33.8%-45.0%] vs. 27.7% [27.6%-27.9%]). In conclusion, individuals with NF1, particularly adults, have poorer cancer survival than the general population. Differences in cancer type and stage at diagnosis contribute but do not fully explain the excess mortality, indicating that factors beyond general health status may play a role.

Abstract Background CLN3 disease, also called Juvenile Neuronal Ceroid Lipofuscinosis (JNCL), or Batten disease, is an ultra‑rare, neurodegenerative lysosomal storage disorder generally affecting individuals during the first decade of life. There can be a delay in diagnosis or misdiagnosis due to a lack of awareness, and when the most common presenting symptom of visual loss is attributed to more common conditions affecting vision. Methods We used a previously published Expert Mapping Tool (EMT) to identify multidisciplinary professionals with diagnostic or clinical management expertise, as well as patient advocates with experience of CLN3 disease. A systematic literature review of published evidence using the Preferred Reporting Items for Systematic Reviews and Meta‑Analyses (PRISMA) guidance was conducted independently and simultaneously to develop key clinical care statements. Each statement was based on the strength of the evidence. The statements formed the basis of an international modified-Delphi consensus process using a virtual meeting platform (Within3). Experts were asked to agree or disagree with each statement and suggest any changes. Statements that reached a consensus of 75% or over are the guiding statements within this manuscript. The processes and manuscript have been independently assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE II) criteria. Results Thirty‑nine international experts from eight specialities were identified, including a patient advocate. Fifty‑three recommendation statements were developed covering eleven domains: General statements, Diagnostics, Clinical Recommendations and Management, Assessments, Social Considerations, Ocular Management, Epilepsy/Seizures, Nutrition, Respiratory Health, Sleep and Rest, and End-of-Life Care. Consensus was reached after one round of voting for all except three statements. The overall AGREE II score for developing these recommendations was 6.4, where 1 represents the lowest and 7 is the highest quality. Conclusion Currently, there are no comprehensive clinical recommendations for CLN3 disease. These recommendations provide a comprehensive, evidence- and consensus‑based tool that can be used by all healthcare professionals involved in the management of CLN3 disease and other similar neurodegenerative conditions. The goal is to address the unmet clinical need for CLN3 disease management and complement other information available.

PURPOSE:Neurofibromatosis 1 (NF1) is associated with reduced life expectancy due to malignancies; however, the risk of nonneoplastic causes of death is less well characterized. METHODS:A total of 1622 persons with NF1, identified through either the Danish National Patient Registry or a clinical database, and 15,856 matched comparators born between 1951 to 2002 were followed from either age 20 or NF1 diagnosis. Death causes were from the Danish Cause of Death Register. Cumulative risks of different causes of death were compared between persons with and without NF1, and years of life lost (YLL) were calculated. RESULTS:Overall, 259 persons with NF1 (16.0%) and 578 comparators (3.6%) died during follow-up. The most frequent nonneoplastic causes of death in NF1 were diseases in the circulatory and nervous systems, with the latter showing a statistically significant higher 70-year cumulative risk in NF1. An excess of 6.1 (4.7-7.5) YLL within age 20 to 60 was seen in NF1 including 2.5 (1.5-3.5) years from nonneoplastic causes, and 3.6 (2.5-4.7) years from neoplasms. CONCLUSION:Persons with NF1 showed an increased risk of death because of nervous system diseases and neoplasms and a reduced life expectancy, with nonneoplastic causes accounting for approximately half of the YLL.

BACKGROUND:Low Apgar scores have been associated with an increased risk of brain injury and neurodevelopmental disorders in newborns with congenital heart defects (CHDs). However, the relation between CHD subtypes and low Apgar scores remains unknown. This study aimed to assess the association between major subtypes of CHD and low (<7) Apgar scores at 5 minutes. METHODS AND RESULTS:This population-based study included 1 040 474 liveborn singletons in Denmark from 1997 to 2013. The association between CHD and low Apgar scores was estimated by confounder-adjusted, multivariable logistic regression. In mediation analyses, the underlying mechanisms were examined. Low Apgar scores were present in 3.0% of newborns with CHD and in 0.7% of newborns without CHD. Overall, CHD was associated with an increased risk of a low Apgar score (adjusted odds ratio, 2.5 [95% CI, 2.1-3.0]). CHD subtypes associated with the highest risks were anomalous pulmonary venous return (adjusted odds ratio, 5.7 [95% CI, 2.2-14.9]), hypoplastic left heart syndrome (adjusted odds ratio, 5.1 [95% CI, 2.2-11.8]), and transposition of the great arteries (adjusted odds ratio, 3.5 [95% CI, 1.7-7.4]). In mediation analyses, preterm birth explained 25.2% (95% CI, 11.8-38.6) of the association between CHD and low Apgar scores. CONCLUSIONS:Nearly all CHD subtypes were associated with an increased risk of a low Apgar score. The association was most pronounced in severe and potentially cyanotic types of CHD. These findings suggest that CHD is associated with a complicated fetal-to-neonatal transition and highlight the potential for improvements of this process in infants with CHD.

Agitation is a common and difficult-to-manage neuropsychiatric syndrome in dementia. Recently, an association with the autonomous nervous system has been suggested. From the literature researched, however, only two studies investigating autonomic function concomitant to agitation situations appeared; one case series comprised two American veterans with vascular and Alzheimer’s dementia, respectively, and in a case series of patients with CLN3 (juvenile neuronal ceroid lipofuscinosis), this was found to be the most common neurodegenerative disease leading to dementia in childhood. In both case series, the measurement of the autonomic system disclosed a parasympathetic withdrawal and sympathetic hyperactivity in the temporal context with agitated behavior. If the time-wise-related autonomic imbalance shown previously can be demonstrated in a larger cohort of patients with Alzheimer’s disease, the use of transcutaneous vagal stimulation might be a potential paradigm shift in the treatment of agitation in Alzheimer’s disease.

As larger population-based studies assessing neoplasm risk in neurofibromatosis 1 (NF1) are limited, we aimed to evaluate overall neoplasm risk, specific cancer types, and second primary cancers. Using Danish registries and clinical databases, we identified 2053 individuals with NF1 and 20,530 population comparisons. We calculated cumulative incidences for first and second primary neoplasms for the study population born 1971–2020 and for adult-onset cancers in the study population born 1951–2020. We used multistate models to estimate the probabilities of being neoplasm-free, having one neoplasm, having ≥two neoplasms or being dead at a certain age. The 50-year cumulative incidence of any first neoplasm was 27.2

OBJECTIVES:The aim of this study is to compare the use of pain coping strategies and pain catastrophizing in youth with and without cerebral palsy (CP), and to examine how these two groups differ with respect to the associations between pain coping, catastrophizing, and measures of psychological function and sleep disturbance. METHODS:Twenty-seven individuals with CP and 49 healthy controls aged 15-22 were included in this cross-sectional observational study. Pain was assessed using a semi-structured interviews and participants completed measures of pain coping, pain catastrophizing, psychological function, and sleep. RESULTS:Youth with CP used information seeking and problem solving (p = 0.003, Cohen's d (d) = -0.80) and sought social support (p = 0.044, d = -0.51) less often, and used internalizing as a coping strategy more often (p = 0.045, d = 0.59) than healthy controls. The use of information seeking and problem solving correlated more strongly with measures of depression (p = 0.023, Cohen's f (f) = 0.08) and sleep disturbance (p = 0.022, f = 0.08), while behavioral distraction correlated more strongly with measures of anxiety (p = 0.006, f = 0.11) and sleep disturbance (p = 0.017, f = 0.09) in youth with CP, compared to healthy controls. CONCLUSIONS:The study findings raise the possibility that youth with CP may benefit more in terms of psychological function and sleep quality from coping training interventions that focus on behavioral distraction, information seeking, and problem solving. Research to test these ideas in additional samples of youth with CP is warranted.

Abstract Background Neurofibromatosis type 1 (NF1) is a genetic condition characterized by various somatic manifestations and cognitive impairments, but the latter are sparsely described in adults. This study aimed at characterizing potential impairments of neurocognitive functions using neuropsychological tests as well as a self-report questionnaire. Methods In a nationwide, population-based study including 103 adults with NF1 and 38 age- and gender-matched NF1-free comparisons, we used a comprehensive neurocognitive test battery to assess intelligence and visual short-term memory, immediate visuospatial recall, reaction time, sustained attention, motor speed, planning, planning time, working memory as well as multitasking and a questionnaire to assess executive functions. Descriptive statistics, multivariate analysis of variance (MANOVA), and general linear models with repeated measure analysis of variance (ANOVA) were used. Results We observed a statistically significant difference in overall performance-based cognitive functioning. Adults with NF1 showed significant, moderate-to-severe impairments in intelligence, visual short-term memory, immediate visuospatial recall, sustained attention (p < 0.0001–0.002), and some executive functions (p = 0.008 − 0.001), whereas other cognitive functions (multitasking, reaction time, motor speed, spatial working memory, planning time, and planning efficacy as well as some self-reported executive functions) were unimpaired. Conclusions This is the first study with a population-based sample of persons with NF1 and the results show impairments of intelligence and other cognitive functions. The pattern of both significant cognitive impairments and non-significantly different cognitive functions suggests a cognitive profile of selective rather than generalized cognitive deficits in NF1.

BackgroundRecurrent non-epileptic episodes of frightened facial and body expression occur in more than half of post-adolescent patients with juvenile neuronal ceroid lipofuscinosis (JNCL, CLN3 disease). Clinically, the episodes look similar to the attacks of paroxysmal sympathetic hyperactivity (PSH) commonly seen following traumatic brain injury (TBI). The episodes occur when the patients are exposed to separation, hear loud sounds or are otherwise bothered by discomfort and as in PSH following TBI, the attacks are difficult to prevent and/or treat.Aim and methodsBased on present knowledge of triggering factors, the neural anxiety/fear circuit, its afferent and efferent pathways and documented CLN3 disease-impact on these tracks, the current study discusses a rational approach how to prevent and/or treat the attacks.ResultsPatients with JNCL have a disturbed somatosensory modulation leading to a reduced threshold of pain; a degeneration within the neural anxiety/fear circuit leading to an imbalance of central network inhibition and excitation pathways; and finally, an, with advancing age, increasing autonomic imbalance leading to a significant dominance of the sympathetic neural system.DiscussionTheoretically, there are three points of attack how to prevent or treat the episodes: (1) increase in threshold of discomfort impact; (2) modulation of imbalance of central network inhibition and excitation, and (3) restoring the balance between the sympathetic and parasympathetic neural systems prompted by a parasympathetic withdrawal. As to (1) and (2), prevention should have the greatest priority. As regards (3), research of transcutaneous vagal stimulation treatment in JNCL is warranted.

BackgroundJuvenile neuronal ceroid lipofuscinosis (JNCL, CLN3) is a childhood-onset neurodegenerative disease with prominent symptoms comprising a pediatric dementia syndrome. As in adult dementia, behavioral symptoms like mood disturbances and anxiety are common. In contrast to in adult dementia, however, the anxious behavioral symptoms increase during the terminal phase of JNCL disease. In the present study, the current understanding of the neurobiological mechanisms of anxiety and anxious behavior in general is addressed as will a discussion of the mechanism of the anxious behavior seen in young JNCL patients. Based on developmental behavioral points of view, known neurobiological mechanisms, and the clinical presentation of the anxious behavior, a theory of its etiology is described. Result and discussionDuring the terminal phase, the cognitive developmental age of JNCL patients is below 2 years. At this stage of mental development individuals act primarily from a concrete world of consciousness and do not have the cognitive ability to encounter a normal anxiety response. Instead, they experience the evolutionary basic emotion of fear, and as the episodes typically are provoked when the adolescent JNCL patient is exposed to either loud sounds, is lifted from the ground, or separated from the mother/known caregiver, the fear can best be perceived as the developmental natural fear-response that appears in children 0-2 years of age. The efferent pathways of the neural fear circuits are mediated through autonomic, neuroendocrine, and skeletal-motor responses. The autonomic activation occurs early, is mediated through the sympathetic and parasympathetic neural systems, and as JNCL patients beyond puberty have an autonomic imbalance with a significant sympathetic hyperactivity, the activation of the autonomic nervous system results in a disproportionate high sympathetic activity resulting in tachycardia, tachypnea, excessive sweating, hyperthermia, and an increased atypical muscle activity. The episodes are thus phenotypically similar to what is seen as Paroxysmal Sympathetic Hyperactivity (PSH) following an acute traumatic brain injury. As in PSH, treatment is difficult and so far, no consensus of a treatment algorithm exists. Use of sedative and analgesic medication and minimizing or avoiding provocative stimuli may partly reduce the frequency and intensity of the attacks. Transcutaneous vagal nerve stimulation might be an option worth to investigate rebalancing the sympathetic-parasympathetic disproportion.

Abstract Background Little is known about employment status, occupation, and disposable income in adults with NF1. Methods From the Danish National Patient Registry and database of two national Centers for Rare Diseases, we identified 1469 adults with NF1, who were matched to 11,991 randomly selected population comparisons on sex and birth year and month. Annual information on employment, occupation and disposable income was ascertained from national registries in 1980–2019. Results Adults with NF1 had a lower odds ratio (OR) for employment [OR 0.71, 95% confidence interval (CI) 0.61–0.83] and higher OR for health-related unemployment (OR 2.94, 95% CI 2.16–3.96) at age 30 years than population comparisons, which persisted at age 40 and 50 years. Somatic diagnoses were associated with a higher OR for health-related unemployment in adults with NF1 than in the population comparisons. Adults with NF1 had a slightly lower disposable income, with a 14% (0.82–0.89) reduction observed among the youngest birth cohort. Furthermore, adults with NF1 were less likely to be in a high skilled occupation at ages 30, 40 and 50 years. Conclusion Adults with NF1 have a lower employment rate, which was mainly due to health-related reasons and a slightly lower disposable income than adults without NF1. Thus, anticipation guidance for employment should be part of the management of NF1 families.

OBJECTIVE:Previous studies have found that neurofibromatosis 1 (NF1) is associated with an increased risk for endocrine disorders, but no comprehensive overview of the risk for specific endocrine disorders has been published. We assessed endocrine morbidity in individuals with NF1 from information on hospital admissions, surgery for endocrine disorders, and relevant medication.DESIGN:A nationwide population registry-based cohort study.METHODS:We identified 2467 individuals with NF1 diagnosed between 1977 and 2013 from the Danish National Patient Register and the RAREDIS database and 20 132 randomly sampled age- and sex-matched population comparisons. Information on endocrine diseases was identified using registrations of discharge diagnoses, surgery, and medication prescriptions. The rates of endocrine disorders in individuals with NF1 were compared with those in the comparison cohort in Cox proportional hazard models.RESULTS:Individuals with NF1 had a higher rate than the comparison group of any endocrine discharge diagnosis (hazard ratio [HR] 1.72, 95% confidence interval [CI]: 1.58-1.87), endocrine-related surgery (2.03, 1.39-2.96), and prescribed medications (1.32, 1.23-1.42). Increased HRs were observed for diseases and surgical operations of several glands, including pheochromocytoma, and for osteoporosis, and osteoporotic fractures. Decreased rates were observed with drugs for type 2 diabetes. Women with NF1 had higher HRs for surgery of the ovaries, uterus, and sterilization, but lower rates of surgeries of cervix and prescriptions for birth control pills.CONCLUSIONS:Neurofibromatosis 1 is associated with a variety of endocrine disorders, surgery, and medication related to endocrine disease. Awareness of endocrine morbidity is important in the clinical follow-up of individuals with NF1.

AIMSTo investigate the association between presence of pain and measures of quality of life domains in children with cerebral palsy (CP) and examine the mediating and moderating effects of pain coping and catastrophizing on the association between pain intensity and measures of function.METHODSCross-sectional study of 81 children with CP completing measures of pain coping, pain catastrophizing, quality of life, pain intensity, pain duration and pain location.RESULTSChildren with CP and pain endorsed significantly lower levels of physical (p < .001) and psychosocial (p = .003) function compared to children with CP having no pain. The use of positive self-statements as a coping strategy moderated the association between pain intensity and psychosocial function (ΔR2= .06, p = .018). Use of internalizing and externalizing pain coping strategies, and pain catastrophizing, emerged as significant mediators of the associations between pain intensity and measures of physical function and psychosocial function.CONCLUSIONPositive self-statements may buffer the effects of pain on psychosocial function in children with CP. Furthermore, catastrophizing and maladaptive coping strategies may explain the relationship between pain intensity and measures of physical and psychosocial function, and are potential targets of interventions. Research to test this idea is warranted.

Purpose The Danish neurofibromatosis 1 (NF1) cohort was initiated to study health-related, socioeconomic and psychological consequences of living with the monogenetic disorder NF1 using a nationwide and population-based approach.Participants The cohort includes all 2467 individuals in Denmark who were hospitalised with or due to NF1 from 1977 to 2013 or registered in the RAREDIS Database (1995–2013), a national clinical database for rare diseases, or both. A comparison cohort matched to individuals with NF1 on sex and date of birth was identified in the Civil Registration System (n=20 132).Findings to date All cohort members were linked to the unique Danish registries to obtain information on hospital contacts, birth outcomes, education and partnership. A questionnaire was completed by 244 of the 629 adult cohort members with NF1 registered in the RAREDIS Database to evaluate the psychosocial and emotional burden. Further, neuropsychological tests were performed on 103 adult cohort members with NF1 and 38 adult population comparisons. To date, six studies have been published. Individuals with NF1 had an increased risk for (1) hospitalisation for disorders affecting all organ systems of the body throughout all decades of life, (2) psychiatric disorders, (3) attaining a short or medium long education and (4) not forming a life partner. Women with NF1 had an increased risk for spontaneous abortions and stillbirths. Finally, adults with NF1 had an impaired quality of life and a high need for professional support for physical, psychological and work-related problems, which was partly associated with disease severity and visibility.Future plans The cohort will regularly be updated with newly diagnosed patients in the RAREDIS Database as well as with outcome information in the Danish registries. New studies are in progress to assess other medical and socioeconomic dimensions of living with NF1.

Children with neurofibromatosis 1 (NF1) may have a high burden of somatic disease and cognitive impairments, which can lead to poor academic performance. We evaluated school grades from exams ending mandatory schooling (usually around age 15 or 16 years) of children with NF1 in a population-based registry study using a within-school matched design. The study included 285 children with NF1 and 12,000 NF1-free peers who graduated from the same school and year during 2002–2015. We estimated overall and gender-specific grades by subject and compared the grades of children with NF1 with those of NF1-free peers in linear regression models. We also examined the effect of social and socioeconomic factors (immigration status and parental education, income and civil status) on grades and age at finalizing ninth grade. School grades varied considerably by socioeconomic stratum for all children; however, children with NF1 had lower grades by an average of 11–12% points in all subjects. In the adjusted models, children with NF1 had significantly lower grades than their NF1-free peers, with largest negative differences in grades observed for girls with NF1. Finally, children with NF1 were 0.2 (CI 0.1–0.2) years older than their peers on graduating from ninth grade, but only maternal educational modified the age at graduating. In conclusion, students with NF1 perform more poorly than their peers in all major school subjects. Gender had a strong effect on the association between NF1 and school grades; however, socioeconomic factors had a similar effect on grades for children with NF1 and their peers.

Abstract Objectives: To compare early neurocognitive development in children born with and without isolated CHD using the Bayley Scales of Infant and Toddler Development (3rd edition) and the Ages and Stages Questionnaire (3rd edition). Methods: Recruitment took place before birth. Women expecting fetuses with and without CHD causing disturbances in the flow of oxygenated blood to the fetal brain were included in a prospective cohort study comprising fetal MRI (previously published) and neurodevelopmental follow-up. We now present the 18- and 36-month neurodevelopmental follow-up using the Bayley Scales according to age and the 6-month-above-age Ages and Stages Questionnaire in 15 children with and 27 children without CHD. Results: Children with CHD had, compared with the children without CHD, an increased risk of scoring ≤ 100 in the Bayley Scales cognition category at 18 and 36 -months; relative risk 1.7 (95% confidence interval (CI): 1.0–2.8) and 3.1 (CI: 1.2–7.5), respectively. They also achieved lower scores in the 6-month-above-age Ages and Stages Questionnaires (24 and 42 months) communication; mean z-score difference −0.72 (CI: −1.4; −0.1) and −1.06 (CI: −1.8; −0.3) and gross motor; mean z-score difference: −0.87 (CI: −1.7; −0.1) and −1.22 (CI: −2.4; −0.02) categories. Conclusions: The children with CHD achieved lower scores in the Bayley Scales cognition category and the Ages and Stages Questionnaire communication and gross motor categories possibly indicative of early neurodevelopmental deficiencies. We recommend early screening and monitoring for neurodevelopmental delays in children with CHD in order to improve further neurodevelopment and educational achievements.

Background The probability of a pregnancy, live birth, stillbirth and abortion has never been assessed in women with neurofibromatosis 1 (NF1) in a large population-based study. Methods We included 1006 women (15-49 years) registered with NF1 in the Danish National Patient Registry or followed in two national Centers for Rare Diseases and 10 020 women from the Danish population. Information on pregnancy outcomes was ascertained from health registries. Cumulative incidence, mean cumulative count, hazard ratios (HRs) and proportion ratios (PRs) with 95% CIs were calculated. Results The cumulative incidence of a first pregnancy at age 50 years was slightly lower in women with NF1 (74%; 95% CI 70 to 77) than in population comparisons (78%; 95% CI 77 to 79). When all pregnancies were included, two pregnancies were expected per woman at age of 50 years, irrespective of a NF1 diagnosis. The hazard of a pregnancy did not differ between women with NF1 (HR 1.03; 95% CI 0.95 to 1.11) and the comparisons after adjustment for somatic and psychiatric disease. The proportion of pregnancies that resulted in a live birth was 63% (783/1252) among women NF1 and 68% (8432/12 465) among the comparisons, yielding a PR of 0.95 (95% CI 0.90 to 1.00). The proportions of stillbirths (PR 2.83; 95% CI 1.63 to 4.93) and spontaneous abortions (PR 1.40; 95% CI 1.09 to 1.79) were increased in women with NF1. Conclusions A similar hazard for pregnancy was observed for women with NF1 and population comparisons after adjustment for potential medical consequences of NF1. However, women with NF1 experienced more spontaneous abortions and stillbirths.

It is well documented that deteriorating heart function due to deposition of ceroid lipopigment is a significant co-morbidity in Juvenile Neuronal Ceroid Lipofuscinosis (CLN3 disease) although the exact disease mechanisms remain unknown in any NCL form. An increasing frequency of cardiac conduction disorders including severe bradycardia and sinus arrest is seen in the late teens, as is a left ventricular hypertrophy in the early 20s. Only a few case reports of pacemaker implantation have been published, and so far, no long-term follow-up study exists. As new treatment options emerge, more patients will live longer and the need for pacemaker will likely increase, why knowledge of long-term outcome is needed. In the present study, we present the course of six patients from the original Danish CLN3-heart population study (n = 29) published in 2011 in whom pacemaker implantation was indicated from a cardiac point of view. In two cases, the families deselected pacemaker implantation. In four males, aged 19-29 years, all having a good general condition, a dual-chamber pacemaker (St. Jude Medical™ Accent/Assurity MRI™) was implanted in general anesthesia without any complications. At follow-up 9 years later, three were still alive. According to the parents' opinion they still have a good quality of life, now 26, 30, and 36 years old. Pacemaker treatment is safe and may have great impact on quality of life. However, the medical indication for pacemaker treatment is relative and it is important that various aspects, including the patient's general condition and family preferences, are thoroughly discussed before making the final decision.

Context 4H or POLR3-related leukodystrophy is an autosomal recessive disorder typically characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism, caused by biallelic pathogenic variants in POLR3A, POLR3B, POLR1C, and POLR3K. The endocrine and growth abnormalities associated with this disorder have not been thoroughly investigated to date. Objective To systematically characterize endocrine abnormalities of patients with 4H leukodystrophy. Design An international cross-sectional study was performed on 150 patients with genetically confirmed 4H leukodystrophy between 2015 and 2016. Endocrine and growth abnormalities were evaluated, and neurological and other non-neurological features were reviewed. Potential genotype/phenotype associations were also investigated. Setting This was a multicenter retrospective study using information collected from 3 predominant centers. Patients A total of 150 patients with 4H leukodystrophy and pathogenic variants in POLR3A, POLR3B, or POLR1C were included. Main Outcome Measures Variables used to evaluate endocrine and growth abnormalities included pubertal history, hormone levels (estradiol, testosterone, stimulated LH and FSH, stimulated GH, IGF-I, prolactin, ACTH, cortisol, TSH, and T4), and height and head circumference charts. Results The most common endocrine abnormalities were delayed puberty (57/74; 77% overall, 64% in males, 89% in females) and short stature (57/93; 61%), when evaluated according to physician assessment. Abnormal thyroid function was reported in 22% (13/59) of patients. Conclusions Our results confirm pubertal abnormalities and short stature are the most common endocrine features seen in 4H leukodystrophy. However, we noted that endocrine abnormalities are typically underinvestigated in this patient population. A prospective study is required to formulate evidence-based recommendations for management of the endocrine manifestations of this disorder.