INTRODUCTION:Pseudohypoparathyroidism 1A (PHP1A) is the best-known representative of inactivating parathyroid hormone (PTH)/PTHrP-signaling disorders (iPPSD). The associated phenotype develops over time and often includes hormonal resistances, short stature, and osteoma cutis. More complex and very early manifestations have also been reported. Neonatal complications may indicate a more severe course of the disease. Here, we report 3 patients with heterozygous GNAS variants and infancy onset of iPPSD2/PHP1A. CASE PRESENTATIONS:Patient 1 is a 15-month-old boy who presented with severe chronic noninfectious diarrhea and elevated thyroid-stimulating hormone (TSH) beginning at 1 month of age, leading to life-threatening failure to thrive. Patient 2 is a 4-year-old boy with a history of bronchopulmonary dysplasia as well as neonatal-onset severe pulmonary complications, including critical pulmonary bleeding and recurring pulmonary infections and TSH elevation. Patient 3 is a 4-year-old girl who exhibited signs of PTH resistance and progressive osteoma cutis at the age of 1-2 weeks and obesity at the age of 3 months. CONCLUSION:The phenotypic spectrum of iPPSD2/PHP1A in neonates and infants may include severe gastrointestinal, pulmonary, and endocrine manifestations, which may delay diagnosis if not recognized as a spectrum disorder of Gsα deficiency. The cases support the hypothesis that early-life manifestations may indicate a more complicated course of the disease. Elevated PTH or TSH in infants with unclear symptoms or conditions should prompt evaluation for disorders of the iPPSD spectrum. In the absence of reliable predictors for the individual courses of PHP1A, in-depth clinical screening for possible manifestations beyond the classical spectrum is warranted even in infancy.

Individuals with ultrarare disorders pose a structural challenge for healthcare systems since expert clinical knowledge is required to establish diagnoses. In TRANSLATE NAMSE, a 3-year prospective study, we evaluated a novel diagnostic concept based on multidisciplinary expertise in Germany. Here we present the systematic investigation of the phenotypic and molecular genetic data of 1,577 patients who had undergone exome sequencing and were partially analyzed with next-generation phenotyping approaches. Molecular genetic diagnoses were established in 32% of the patients totaling 370 distinct molecular genetic causes, most with prevalence below 1:50,000. During the diagnostic process, 34 novel and 23 candidate genotype–phenotype associations were identified, mainly in individuals with neurodevelopmental disorders. Sequencing data of the subcohort that consented to computer-assisted analysis of their facial images with GestaltMatcher could be prioritized more efficiently compared with approaches based solely on clinical features and molecular scores. Our study demonstrates the synergy of using next-generation sequencing and phenotyping for diagnosing ultrarare diseases in routine healthcare and discovering novel etiologies by multidisciplinary teams.

Most individuals with rare diseases initially consult their primary care physician. For a subset of rare diseases, efficient diagnostic pathways are available. However, ultra-rare diseases often require both expert clinical knowledge and comprehensive genetic diagnostics, which poses structural challenges for public healthcare systems. To address these challenges within Germany, a novel structured diagnostic concept, based on multidisciplinary expertise at established university hospital centers for rare diseases (CRDs), was evaluated in the three year prospective study TRANSLATE NAMSE. A key goal of TRANSLATE NAMSE was to assess the clinical value of exome sequencing (ES) in the ultra-rare disease population. The aims of the present study were to perform a systematic investigation of the phenotypic and molecular genetic data of TRANSLATE NAMSE patients who had undergone ES in order to determine the yield of both ultra-rare diagnoses and novel gene-disease associations; and determine whether the complementary use of machine learning and artificial intelligence (AI) tools improved diagnostic effectiveness and efficiency. ES was performed for 1,577 patients (268 adult and 1,309 pediatric). Molecular genetic diagnoses were established in 499 patients (74 adult and 425 pediatric). A total of 370 distinct molecular genetic causes were established. The majority of these concerned known disorders, most of which were ultra-rare. During the diagnostic process, 34 novel and 23 candidate genotype-phenotype associations were delineated, mainly in individuals with neurodevelopmental disorders. To determine the likelihood that ES will lead to a molecular diagnosis in a given patient, based on the respective clinical features only, we developed a statistical framework called YieldPred. The genetic data of a subcohort of 224 individuals that also gave consent to the computer-assisted analysis of their facial images were processed with the AI tool Prioritization of Exome Data by Image Analysis (PEDIA) and showed superior performance in variant prioritization. The present analyses demonstrated that the novel structured diagnostic concept facilitated the identification of ultra-rare genetic disorders and novel gene-disease associations on a national level and that the machine learning and AI tools improved diagnostic effectiveness and efficiency for ultra-rare genetic disorders.

BackgroundChildhood primary brain tumors (CPBT) are the second largest group of childhood malignancies and associated with a high risk for endocrine late effects.ObjectiveTo assess endocrine late effects and their relevance for the development of osteopathologies in survivors.MethodsThis single center cross sectional study investigated data from 102 CPBT survivors with a mean age of 13.0 years and a mean age at diagnosis of 8.7 years. Clinical, biochemical, radiographic, and anamnestic data regarding endocrine and bone health were obtained at study visits. In addition, data regarding tumor stage and therapy was obtained by chart review. An expert opinion was applied to define presence of osteopathologies.ResultsImpaired bone health, defined by at least one pathological screening parameter, was present in 65% of patients. 27.5% were found to have overt osteopathologies per expert opinion. 37.8% displayed a severe vitamin D deficiency (25-OH vitamin D < 10 ng/ml) and 11% a secondary hyperparathyroidism. Patients with osteopathologies had lower 25-OH vitamin D levels compared to patients without osteopathologies. Multiple endocrine late effects were present: diabetes insipidus in 10.8%, aberrant pubertal development in 13.7%, central hypocortisolism in 14.9%, thyroid dysfunction in 23.8% and growth hormone deficiency in 21.8%. A total of 31.3% of survivors displayed any endocrinopathy. Tumors located near hypothalamic structures and patients who received irradiation had a higher likelihood of endocrine morbidity.ConclusionThis study indicates that endocrine deficiencies are common in pediatric survivors of CPBTs. Osteopathologies are present in this cohort. A prominent effect of hormonal deficiencies on bone health was not detected, possibly because patients were sufficiently treate for their endocrine conditions or indicating resilience of the childhood bone remodeling process. Vitamin D deficiency is frequent and should be treated as recommended.

Postzygotic mosaicism (PZM) in NIPBL is a strong source of causality for Cornelia de Lange syndrome (CdLS) that can have major clinical implications. Here, we further delineate the role of somatic mosaicism in CdLS by describing a series of 11 unreported patients with mosaic disease-causing variants in NIPBL and performing a retrospective cohort study from a Spanish CdLS diagnostic center. By reviewing the literature and combining our findings with previously published data, we demonstrate a negative selection against somatic deleterious NIPBL variants in blood. Furthermore, the analysis of all reported cases indicates an unusual high prevalence of mosaicism in CdLS, occurring in 13.1% of patients with a positive molecular diagnosis. It is worth noting that most of the affected individuals with mosaicism have a clinical phenotype at least as severe as those with constitutive pathogenic variants. However, the type of genetic change does not vary between germline and somatic events and, even in the presence of mosaicism, missense substitutions are located preferentially within the HEAT repeat domain of NIPBL. In conclusion, the high prevalence of mosaicism in CdLS as well as the disparity in tissue distribution provide a novel orientation for the clinical management and genetic counselling of families.

OBJECTIVE:The study was undertaken to determine the prevalence of subclinical and overt thyroid dysfunction as well as thyroid autoimmunity in depressed adolescents in comparison to the general pediatric population. Additionally, the relationship between parameters of thyroid function and Beck Depression Inventory-II (BDI-II) scores was examined.METHODS:Parameters of thyroid function (thyrotropin, free thyroxine, thyroid peroxidase antibodies) and prevalence of thyroid dysfunction and autoimmunity were determined in 360 adolescents (11-19 years) with at least mild depression (BDI-II score > 13) between June 2016 and December 2019 and in a representative reference cohort without evidence of impaired mental health from a nationwide survey (German Health Interview and Examination Survey for Children and Adolescents [KiGGS], 2003-2006).RESULTS:There was a higher prevalence of thyroid peroxidase antibody positivity in depressed adolescents (mean ± SD BDI-II, 30.0 ± 10.4) compared to KiGGS participants (depressed adolescents: 5.8%, 95% CI [3.7-8.6]; odds ratio [OR] 1.9, P = .009, d = 0.36; KiGGS participants: 3.1%, 95% CI [2.5-3.9]). The prevalence of subclinical hypothyroidism was likewise higher in depressed adolescents (9.1%, 95% CI [6.3-12.4] vs KiGGS participants: 2.1%, 95% CI [1.6-2.7]; OR 4.7, P < .001, d = 0.85), but no other types of thyroid dysfunction had a higher prevalence. There was no significant relationship between parameters of thyroid function and BDI-II scores, as examined by multiple regression considering relevant covariates. The positive results were verified in a subsample of patients with a confirmed diagnosis of depression (N = 284).CONCLUSIONS:The prevalence of subclinical hypothyroidism and of thyroid autoimmunity in depressed adolescents is increased. The etiology of these observations is not well understood, and further studies to examine the underlying relationship are required. Moreover, thyroid autoimmunity may constitute an additional risk factor for depression on its own.

Phosphatidylinositol 4-kinase IIIα (PI4KIIIα/PI4KA/OMIM:600286) is a lipid kinase generating phosphatidylinositol 4-phosphate (PI4P), a membrane phospholipid with critical roles in the physiology of multiple cell types. PI4KIIIα's role in PI4P generation requires its assembly into a heterotetrameric complex with EFR3, TTC7 and FAM126. Sequence alterations in two of these molecular partners, TTC7 (encoded by TTC7A or TCC7B) and FAM126, have been associated with a heterogeneous group of either neurological (FAM126A) or intestinal and immunological (TTC7A) conditions. Here we show that biallelic PI4KA sequence alterations in humans are associated with neurological disease, in particular hypomyelinating leukodystrophy. In addition, affected individuals may present with inflammatory bowel disease, multiple intestinal atresia and combined immunodeficiency. Our cellular, biochemical and structural modelling studies indicate that PI4KA-associated phenotypical outcomes probably stem from impairment of PI4KIIIα-TTC7-FAM126's organ-specific functions, due to defective catalytic activity or altered intra-complex functional interactions. Together, these data define PI4KA gene alteration as a cause of a variable phenotypical spectrum and provide fundamental new insight into the combinatorial biology of the PI4KIIIα-FAM126-TTC7-EFR3 molecular complex.

Background: Impaired bone health is a late effect of childhood malignancies which can be difficult to detect in juvenile survivors. It may, however, lead to compromised quality of life, or even permanent disability later in life due to osteoporosis, pain or fractures if left untreated. Acute lymphoblastic leukemia (ALL) is the most frequent childhood malignancy with an over 85% five-year survival. ALL and its treatment cause bone alterations in adults, but little information on the bone health status in juvenile survivors is available. Objective: To report data on skeletal late effects in juvenile survivors of childhood ALL based on a comprehensive assessment of bone health and to assess the influence of a vitamin D deficiency on bone health in this cohort. Methods: In a single center cross sectional study 128 pediatric patients (11.9 ± 4.76 years) with a mean follow up of 5.88 ± 3.75 years after diagnosis of ALL were recruited. The bone health status of the survivors was assessed based on clinical examination, review of medical records, biochemical and radiographic analyses, by clinical experts. A score which utilized 8 different parameters was formed and used to assess the effect of a vitamin D deficiency on bone health. Results: In this cohort, 18% of survivors displayed overt osteopathologies as defined by clinical expert assessment. Impaired bone health, defined by at least one pathological screening parameter, was detected in 77%. Despite recommendations for adequate vitamin D supplementation, 15% displayed a vitamin D deficiency associated with hyperparathyroidism. The applied score identified survivors with osteopathologies with high sensitivity and specificity. The median score did not differ between patients without and with severe vitamin D deficiency. Conclusion: Our findings suggest that impaired bone health and osteopathologies are common skeletal late effects following treatment of childhood ALL. Major contributing factors are BMT, irradiation and older age at diagnosis. Vitamin D deficiency likely accounts for hyperparathyroidism in some patients but does not seem to further affect bone health in this cohort. Survivors of ALL need thorough surveillance to investigate bone health, since bone morbidity is common and still poorly understood. Early detection and appropriate intervention may improve bone health.

Pseudohypoparathyroidism 1A (PHP1A) consists of signs of Albright hereditary osteodystrophy (AHO) and multiple, variable hormonal resistances. Elevated PTH levels are the biochemical hallmark of the disease. Short stature in PHP1A may be caused by a form of accelerated chondrocyte differentiation leading to premature growth plate closure, possibly in combination with GH deficiency in some patients. Treatment of short stature with recombinant growth hormone (rhGH) in pediatric patients may improve final height if started during childhood. The 10 11/12-year-old boy with clinical signs of AHO presented for evaluation of short stature [height standard deviation score (SDS) -2.72]. Clinically his mother was affected by AHO as well. A heterozygous mutation c.505G>A (p.E169K) in exon 6 of the GNAS gene confirmed a diagnosis of PHP1A in the boy. However, hormonal assessment was unremarkable except for low serum IGF-1 (SDS -2.67). On follow-up, GH deficiency due to GHRH resistance was suspected and confirmed by clonidine and arginine stimulation tests. Treatment with rhGH (0.035 mg/kg) for 2 years resulted in catch-up growth (height SDS -1.52). At age 15 years the PTH levels and bone age of the patient remain within the normal range. In patients with PHP1A, short stature is caused by the effects of Gs-α deficiency on the growth plate. However, resistance to GHRH and the resulting GH deficiency might also contribute. Recombinant GH treatment increases growth in these patients. Diagnostic workup for GH deficiency as a factor contributing to short stature is recommended even in the absence of other hormonal resistances.