Objective: Maternal thrombophilia is a risk factor for adverse pregnancy outcomes. The aim of this study was to elucidate the controversial role of fetal and paternal thrombophilia in the development of severe placenta-mediated pregnancy complications. Study Design: The study group comprised 126 mothers, 72 fetuses and 58 fathers. 111 mothers, 50 fetuses and 91 fathers acted as controls. 106 couples were selected to study the thrombophilias of paternal inheritance, 58 from the study group and 48 from the control group. The prevalence of factor V Leiden mutation, prothrombin G20210A mutation and homozygous 10-methylenetetrahydrofolate reductase C677 T mutations were compared between the study and control groups to study whether maternal, fetal or paternal thrombophilias increase the risk of severe preeclampsia, intrauterine growth restriction, placental abruption and stillbirth. Results: The total prevalence of fetal thrombophilic mutations was 8.3% in the study group and 14.0% in the control group. Paternal prevalence of thrombophilic mutations was 6.8% and 4.3%, respectively. There were no statistical differences between fetal or paternal thrombophilic mutations between the study and control groups. Conclusion: Fetal or paternal factor V Leiden mutation is not associated with severe placenta-mediated pregnancy complications. (C) 2018 Elsevier B.V. All rights reserved.
Coffin-Siris syndrome (CSS) is a rare intellectual disability syndrome classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and other digits, distinctive facial features, hirsutism/hypertrichosis, and sparce scalp hair. It is genetically heterogeneous but most often caused by a pathogenic variant in the ARID1B gene. Previous clinical reports of CSS patients are mainly based on young or middle-aged individuals. Here, we report a 69-year-old woman with CSS phenotype and a pathogenic ARID1B loss-of-function variant c.5259_5260dup. She has severe intellectual disability but otherwise she is in relatively good health both physically and mentally. There is no evident history of chronic illness or progressive disability. CSS appears to be compatible with long survival and most likely it is underdiagnosed in geriatric patients with intellectual disability.
Pathogenic sequence variants in the solute carrier family 26 member 2 (SLC26A2) gene result in lethal (achondrogenesis Ib and atelosteogenesis II) and non-lethal (diastrophic dysplasia and recessive multiple epiphyseal dysplasia, rMED) chondrodysplasias. We report on two new patients with rMED and very rare compound heterozygous mutation combinations in non-consanguineous families. Patient I presented in childhood with waddling gait and joint stiffness. Radiographs showed epiphyseal changes, bilateral coxa plana-deformity and knee valgus deformity, for which he underwent surgeries. At present 33 years his height is 165 cm. Patient II presented with cleft palate, small jaw, short limbs, underdeveloped thumbs and on radiographs, cervical kyphosis with an underdeveloped C4. He also developed severe scoliosis but has grown at -2.9 SD curve. Molecular analysis revealed that patient I is heterozygous for two known pathogenic variants in SLC26A2, a splice site variant c.-26+2T > C and a missense variant c.1957T > A (p.Cys653Ser), while patient II is compound heterozygous for missense variants c.835C > T (p.Arg279Trp) and c.1535C > A (p.Thr512Lys). These patients further elucidate the variability of the phenotypic and genetic presentations of rMED.
Channelopathies are disorders caused by abnormal ion channel function in differentiated excitable tissues. We discovered a unique neurodevelopmental channelopathy resulting from pathogenic variants in SCN3A, a gene encoding the voltage-gated sodium channel NaV1.3. Pathogenic NaV1.3 channels showed altered biophysical properties including increased persistent current. Remarkably, affected individuals showed disrupted folding (polymicrogyria) of the perisylvian cortex of the brain but did not typically exhibit epilepsy; they presented with prominent speech and oral motor dysfunction, implicating SCN3A in prenatal development of human cortical language areas. The development of this disorder parallels SCN3A expression, which we observed to be highest early in fetal cortical development in progenitor cells of the outer subventricular zone and cortical plate neurons and decreased postnatally, when SCN1A (NaV1.1) expression increased. Disrupted cerebral cortical folding and neuronal migration were recapitulated in ferrets expressing the mutant channel, underscoring the unexpected role of SCN3A in progenitor cells and migrating neurons.
Osteoarthritis (OA) is the most common degenerative joint disorder and genetic factors have been shown to have a significant role in its etiology. The first metatarsophalangeal joint (MTP I) is highly susceptible to development of OA due to repetitive mechanical stress during walking. We used whole exome sequencing to study genetic defect(s) predisposing to familial early-onset bilateral MTP I OA inherited in an autosomal dominant manner. A nonsynonymous single nucleotide variant rs41310883 (c.524C>T, p.Thr175Met) in TUFT1 gene was found to co-segregate perfectly with MTP I OA. The role of TUFT1 and the relevance of the identified variant in pathogenesis of MTP I OA were further assessed using functional in vitro analyses. The variant reduced TUFT1 mRNA and tuftelin protein expression in HEK293 cells. ATDC5 cells overexpressing wild type (wt) or mutant TUFT1 were cultured in calcifying conditions and chondrogenic differentiation was found to be inhibited in both cell populations, as indicated by decreased marker gene expression when compared with the empty vector control cells. Also, the formation of cartilage nodules was diminished in both TUFT1 overexpressing ATDC5 cell populations. At the end of the culturing period the calcium content of the extracellular matrix was significantly increased in cells overexpressing mutant TUFT1 compared to cells overexpressing wt TUFT1 and control cells, while the proteoglycan content was reduced. These data imply that overexpression of TUFT1 in ATDC5 inhibits chondrogenic differentiation, and the identified variant may contribute to the pathogenesis of OA by increasing calcification and reducing amount of proteoglycans in the articular cartilage extracellular matrix thus making cartilage susceptible for degeneration and osteophyte formation.
Background: Congenital hypothyroidism (CH) is defined as the lack of thyroid hormones at birth. Mutations in at least 15 different genes have been associated with this disease. While up to 20% of CH cases are hereditary, the majority of cases are sporadic with unknown etiology. Apart from a monogenic pattern of inheritance, multigenic mechanisms have been suggested to play a role in CH. The genetics of CH has not been studied in Finland so far. Therefore, multigenic sequencing of CH candidate genes was performed in a Finnish patient cohort with both familial and sporadic CH. Methods: A targeted next-generation sequencing (NGS) panel, covering all exons of the major CH genes, was applied for 15 patients with sporadic and 11 index cases with familial CH. Results: Among the familial cases, six pathogenic mutations were found in the TPO, PAX8, and TSHR genes. Furthermore, pathogenic NKX2.1 and TG mutations were identified from sporadic cases, together with likely pathogenic variants in the TG, NKX2.5, SLC26A4, and DUOX2 genes. All identified novel pathogenic mutations were confirmed by Sanger-sequencing and characterized in silico and/or in vitro. Conclusion: In summary, the CH panel provides an efficient, cost-effective, and multigenic screening tool for both known and novel CH gene mutations. Hence, it may be a useful method to identify accurately the genetic etiology for dyshormogenic, familial, or syndromic forms of CH.
We present two siblings (a boy and a girl) with a submicroscopic 4 Mb duplication at 22q13.1q13.2. Both children manifested infantile hypotonia and delayed motor milestones, congenital heart defect, growth deficiency, and strikingly similar and distinctive craniofacial dysmorphism including brachycephaly, blepharophimosis, short broad-based nose and wide mouth with thin upper lip. The boy had also a submucous cleft palate. Both had fair skin and hair compared with their parents. Both had moderate mental retardation associated with a short attention span. A 4-Mb interstitial duplication at 22q13.1q13.2 was detected by whole genome microarray comparative genomic hybridisation (array CGH) in both children. The duplication was confirmed by fluorescence in situ hybridisation (FISH) analysis. Their parents had normal array CGH results. FISH analysis revealed that the father was a carrier of a balanced interchromosomal submicroscopic insertion of 22q13 into chromosome 11q23, explaining the unbalanced aberration detected in both children. This report narrows down the critical region at 22q13.1q13.2, which is associated with mental retardation, pre- and post-natal growth retardation, hippocampal malformation, psychiatric symptoms such as short attention span and facial dysmorphism including hypertelorism, epicanthal folds and low set/abnormal ears.
American Journal of Medical Genetics Part AVolume 161, Issue 6 p. 1491-1494 Research Letter Recessive MED with auricular swelling due to compound heterozygosity Arg279Tpr/Thr512Lys in the SLC26A2 gene Johanna Syvänen, Corresponding Author Johanna Syvänen Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Turku, Finland Department of Orthopaedic Surgery, Turku University Central Hospital, Turku, Finland Correspondence to: Johanna Syvänen, MD, Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Kiinanmyllynkatu 4-8, Turku 20520, Finland. E-mail: [email protected]Search for more papers by this authorIlkka Helenius, Ilkka Helenius Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Turku, FinlandSearch for more papers by this authorMatti Hero, Matti Hero Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, FinlandSearch for more papers by this authorOuti Mäkitie, Outi Mäkitie Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland Folkhälsan Institute of Genetics, Helsinki, FinlandSearch for more papers by this authorJaakko Ignatius, Jaakko Ignatius Department of Clinical Genetics, Turku University Central Hospital, Turku, FinlandSearch for more papers by this author Johanna Syvänen, Corresponding Author Johanna Syvänen Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Turku, Finland Department of Orthopaedic Surgery, Turku University Central Hospital, Turku, Finland Correspondence to: Johanna Syvänen, MD, Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Kiinanmyllynkatu 4-8, Turku 20520, Finland. E-mail: [email protected]Search for more papers by this authorIlkka Helenius, Ilkka Helenius Department of Paediatric Orthopaedic Surgery, Turku University Central Hospital, Turku, FinlandSearch for more papers by this authorMatti Hero, Matti Hero Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, FinlandSearch for more papers by this authorOuti Mäkitie, Outi Mäkitie Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland Folkhälsan Institute of Genetics, Helsinki, FinlandSearch for more papers by this authorJaakko Ignatius, Jaakko Ignatius Department of Clinical Genetics, Turku University Central Hospital, Turku, FinlandSearch for more papers by this author First published: 23 April 2013 https://doi.org/10.1002/ajmg.a.35872Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume161, Issue6June 2013Pages 1491-1494 RelatedInformation
CONTEXT:Maternally inherited 3-kb STX16 deletions cause autosomal dominant pseudohypoparathyroidism type Ib (PHP-Ib) characterized by PTH resistance with loss of methylation restricted to the GNAS exon A/B.OBJECTIVE:The objective of the study was to search for the 3-kb STX16 deletion and to establish haplotypes for the GNAS region for two PHP-Ib patients and their families.SETTING:The study was conducted at a research laboratory and tertiary care hospitals.PATIENTS:The index cases presented at the ages 8 and 9.5 yr, respectively, with hypocalcemia, hyperphosphatemia, and elevated PTH.INTERVENTIONS:There were no interventions.RESULTS:DNA analyses of the index cases revealed an isolated loss of the GNAS exon A/B methylation and the 3-kb STX16 deletion. In the first family, the patient's healthy mother and sister showed no genetic or epigenetic abnormality, yet microsatellite analysis of the GNAS region indicated that both siblings share the same maternal allele, with the exception of an allelic loss for marker 261P9-CA1 (located within STX16), leading to the conclusion that a de novo mutation had occurred on the maternal allele. In the second family, three siblings of the index case are also affected, and an analysis of their DNA revealed the 3-kb STX16 deletion, which was also found in the healthy mother and a maternal uncle. Analysis of the siblings of the deceased maternal grandfather and some of their descendants excluded the 3-kb STX16 deletion, but haplotype analysis of the GNAS region suggested that he had acquired the mutation de novo.CONCLUSIONS:De novo 3-kb STX16 deletions, reported only once previously, are infrequent but should be excluded in all cases of PHP-Ib, even when the family history is negative for an inherited form of this disorder.
BACKGROUND:Only 29 cases of constitutional 9q22 deletions have been published and all have been sporadic. Most associate with Gorlin syndrome or nevoid basal cell carcinoma syndrome (NBCCS, MIM #109400) due to haploinsufficiency of the PTCH1 gene (MIM *601309).METHODS AND RESULTS:We report two mentally retarded female siblings and their cognitively normal father, all carrying a similar 5.3 Mb microdeletion at 9q22.2q22.32, detected by array CGH (244 K). The deletion does not involve the PTCH1 gene, but instead 30 other gene,s including the ROR2 gene (MIM *602337) which causing both brachydactyly type 1 (MIM #113000) and Robinow syndrome (MIM #268310), and the immunologically active SYK gene (MIM *600085). The deletion in the father was de novo and FISH analysis of blood lymphocytes did not suggest mosaicism. All three patients share similar mild dysmorphic features with downslanting palpebral fissures, narrow, high bridged nose with small nares, long, deeply grooved philtrum, ears with broad helix and uplifted lobuli, and small toenails. All have significant dysarthria and suffer from continuous middle ear and upper respiratory infections. The father also has a funnel chest and unilateral hypoplastic kidney but the daughters have no malformations.CONCLUSIONS:This is the first report of a familial constitutional 9q22 deletion and the first deletion studied by array-CGH which does not involve the PTCH1 gene. The phenotype and penetrance are variable and the deletion found in the cognitively normal normal father poses a challenge in genetic counseling.
We present a family with mild developmental delay and a duplication (6)(p22.2). Array CGH analyses revealed this 0.7 Mb duplication in all three patients, spanning candidate genes ALDH5A1, DCDC2, and KIAA0319. Results were confirmed by MLPA analysis of the dyslexia genes DCDC2 and KIAA0319. Of interest, ALDH5A1 encodes succinate semialdehyde dehydrogenase (SSADH), an enzyme responsible for γ-amino-butyric acid (GABA) degradation. Inherited deficiency of SSADH results in accumulation of the neuromodulator γ-hydroxybutyrate (GHB), which likely contributes to some aspects of the neurological phenotype of SSADH deficiency (MIM #271980). Based on autosomal-recessive inheritance, we sequenced ALDH5A1 in all patients, which revealed no pathogenic mutations. SSADH enzyme studies in cultured white cells confirmed elevated SSADH activity, consistent with the duplication, whereas concentrations of SSA were slightly elevated in urine, suggesting oxidant stress. We speculate that the duplication (6)(p22.2) and corresponding hyperactive level of SSADH activity may have negative consequences for GABA metabolism and the role of SSADH in other metabolic sequences.
We analyzed the frequency and possible causes of false-negative (Fn) screening results in first-trimester combined Down syndrome screening in Finland. During the study period (May 1, 2002, to December 31, 2008), 76,949 voluntary women with singleton pregnancies participated in screening. Maternal age at screening, week of gestation, levels of pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (fβ-hCG), and nuchal translucency (NT) measurement were compared and statistically analyzed between true-positive (Tp) and Fn cases. There were a total of 188 Down syndrome cases (1:409) in the screened population; 154 confirmed Tp and 34 Fn cases. Most Fn cases (n = 25) occurred at 12 + 0 to 13 + 6 weeks' gestation and only nine Fn cases presented between 10 and 11 weeks' gestation. According to the logistic regression analysis, the NT measurement was the most powerful discriminating factor in Fn screening results and accounted for 37.2% of Fn results. The second most important factor was fβ-hCG, adding 14.0% to R 2, followed by PAPP-A, which contributed a further 14.3%. The chosen parameters explain 83.9% of Fn results, but 16.1% remain due to unknown factor(s). All investigated parameters contributed to Fn screening results, but fetal NT was the most discriminating factor leading to an Fn screening result.
The autosomal recessive kidney disease nephronophthisis (NPHP) constitutes the most frequent genetic cause of terminal renal failure in the first 3 decades of life. Ten causative genes (NPHP1-NPHP9 and NPHP11), whose products localize to the primary cilia-centrosome complex, support the unifying concept that cystic kidney diseases are "ciliopathies". Using genome-wide homozygosity mapping, we report here what we believe to be a new locus (NPHP-like 1 [NPHPL1]) for an NPHP-like nephropathy. In 2 families with an NPHP-like phenotype, we detected homozygous frameshift and splice-site mutations, respectively, in the X-prolyl aminopeptidase 3 (XPNPEP3) gene. In contrast to all known NPHP proteins, XPNPEP3 localizes to mitochondria of renal cells. However, in vivo analyses also revealed a likely cilia-related function; suppression of zebrafish xpnpep3 phenocopied the developmental phenotypes of ciliopathy morphants, and this effect was rescued by human XPNPEP3 that was devoid of a mitochondrial localization signal. Consistent with a role for XPNPEP3 in ciliary function, several ciliary cystogenic proteins were found to be XPNPEP3 substrates, for which resistance to N-terminal proline cleavage resulted in attenuated protein function in vivo in zebrafish. Our data highlight an emerging link between mitochondria and ciliary dysfunction, and suggest that further understanding the enzymatic activity and substrates of XPNPEP3 will illuminate novel cystogenic pathways.