Our study revealed that drinking during pregnancy is fairly common, three times the levels reported in surveys that ask only about drinking during the month before the survey. Women who binge drink before pregnancy are at particular risk for drinking after becoming pregnant. Sexually active women of childbearing ages who drink alcohol should be advised to use reliable methods to prevent pregnancy, plan their pregnancies, and stop drinking before becoming pregnant.
Freeman-Sheldon syndrome, or distal arthrogryposis type 2A (DA2A), is an autosomal-dominant condition caused by mutations in MYH3 and characterized by multiple congenital contractures of the face and limbs and normal cognitive development. We identified a subset of five individuals who had been putatively diagnosed with "DA2A with severe neurological abnormalities" and for whom congenital contractures of the limbs and face, hypotonia, and global developmental delay had resulted in early death in three cases; this is a unique condition that we now refer to as CLIFAHDD syndrome. Exome sequencing identified missense mutations in the sodium leak channel, non-selective (NALCN) in four families affected by CLIFAHDD syndrome. We used molecular-inversion probes to screen for NALCN in a cohort of 202 distal arthrogryposis (DA)-affected individuals as well as concurrent exome sequencing of six other DA-affected individuals, thus revealing NALCN mutations in ten additional families with "atypical" forms of DA. All 14 mutations were missense variants predicted to alter amino acid residues in or near the S5 and S6 pore-forming segments of NALCN, highlighting the functional importance of these segments. In vitro functional studies demonstrated that NALCN alterations nearly abolished the expression of wild-type NALCN, suggesting that alterations that cause CLIFAHDD syndrome have a dominant-negative effect. In contrast, homozygosity for mutations in other regions of NALCN has been reported in three families affected by an autosomal-recessive condition characterized mainly by hypotonia and severe intellectual disability. Accordingly, mutations in NALCN can cause either a recessive or dominant condition characterized by varied though overlapping phenotypic features, perhaps based on the type of mutation and affected protein domain(s).
Neurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders, affecting 1:3,000 worldwide. Identification of genotype–phenotype correlations is challenging because of the wide range clinical variability, the progressive nature of the disorder, and extreme diversity of the mutational spectrum. We report 136 individuals with a distinct phenotype carrying one of five different NF1 missense mutations affecting p.Arg1809. Patients presented with multiple café‐au‐lait macules (CALM) with or without freckling and Lisch nodules, but no externally visible plexiform neurofibromas or clear cutaneous neurofibromas were found. About 25% of the individuals had Noonan‐like features. Pulmonic stenosis and short stature were significantly more prevalent compared with classic cohorts (P < 0.0001). Developmental delays and/or learning disabilities were reported in over 50% of patients. Melanocytes cultured from a CALM in a segmental NF1‐patient showed two different somatic NF1 mutations, p.Arg1809Cys and a multi‐exon deletion, providing genetic evidence that p.Arg1809Cys is a loss‐of‐function mutation in the melanocytes and causes a pigmentary phenotype. Constitutional missense mutations at p.Arg1809 affect 1.23% of unrelated NF1 probands in the UAB cohort, therefore this specific NF1 genotype–phenotype correlation will affect counseling and management of a significant number of patients.
Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80% of cases with typical facies. Mutations in the core cohesin complex proteins, encoded by the SMC1A, SMC3 and RAD21 genes, together account for ∼5% of subjects, often with atypical CdLS features. Recently, we identified mutations in the X-linked gene HDAC8 as the cause of a small number of CdLS cases. Here, we report a cohort of 38 individuals with an emerging spectrum of features caused by HDAC8 mutations. For several individuals, the diagnosis of CdLS was not considered prior to genomic testing. Most mutations identified are missense and de novo. Many cases are heterozygous females, each with marked skewing of X-inactivation in peripheral blood DNA. We also identified eight hemizygous males who are more severely affected. The craniofacial appearance caused by HDAC8 mutations overlaps that of typical CdLS but often displays delayed anterior fontanelle closure, ocular hypertelorism, hooding of the eyelids, a broader nose and dental anomalies, which may be useful discriminating features. HDAC8 encodes the lysine deacetylase for the cohesin subunit SMC3 and analysis of the functional consequences of the missense mutations indicates that all cause a loss of enzymatic function. These data demonstrate that loss-of-function mutations in HDAC8 cause a range of overlapping human developmental phenotypes, including a phenotypically distinct subgroup of CdLS.
Charcot-Marie-Tooth disease is a genetically heterogeneous group of motor and sensory neuropathies associated with mutations in more than 30 genes. Charcot-Marie-Tooth disease type 4J (OMIM 611228) is a recessive, potentially severe form of the disease caused by mutations of the lipid phosphatase FIG4. We provide a more complete view of the features of this disorder by describing 11 previously unreported patients with Charcot-Marie-Tooth disease type 4J. Three patients were identified from a small cohort selected for screening because of their early onset disease and progressive proximal as well as distal weakness. Eight patients were identified by large-scale exon sequencing of an unselected group of 4000 patients with Charcot-Marie-Tooth disease. In addition, 34 new FIG4 variants were detected. Ten of the new CMT4J cases have the compound heterozygous genotype FIG4(I41T/null) described in the original four families, while one has the novel genotype FIG4(L17P/nul)(l). The population frequency of the I41T allele was found to be 0.001 by genotyping 5769 Northern European controls. Thirty four new variants of FIG4 were identified. The severity of Charcot-Marie-Tooth disease type 4J ranges from mild clinical signs to severe disability requiring the use of a wheelchair. Both mild and severe forms have been seen in patients with the same genotype. The results demonstrate that Charcot-Marie-Tooth disease type 4J is characterized by highly variable onset and severity, proximal as well as distal and asymmetric muscle weakness, electromyography demonstrating denervation in proximal and distal muscles, and frequent progression to severe amyotrophy. FIG4 mutations should be considered in Charcot-Marie-Tooth patients with these characteristics, especially if found in combination with sporadic or recessive inheritance, childhood onset and a phase of rapid progression.
IMPORTANCE Birth defects affect approximately 1 in 33 children. Some birth defects are known to be strongly associated with childhood cancer (eg, trisomy 21 and acute leukemia). However, comprehensive evaluations of childhood cancer risk in those with birth defects have been limited in previous studies by insufficient sample sizes. OBJECTIVES To identify specific birth defect-childhood cancer (BD-CC) associations and characterize cancer risk in children by increasing number of nonchromosomal birth defects. DESIGN, SETTING, AND PARTICIPANTS This multistate, population-based registry linkage study pooled statewide data on births, birth defects, and cancer from Texas,
In Texas, most anotia/microtia cases were in the unilateral and microtia groups, and 45% were isolated. Several clinical subgroups exhibited higher prevalence in males and among older mothers. Relative to whites, blacks were at lower risk and Hispanics (especially Mexico-born mothers) were at higher risk for selected types of anotia/microtia.
Raine syndrome is an osteosclerotic bone dysplasia, which has proved to be lethal within the first few weeks of life in all the reported cases to date. We recently identified a chromosomal rearrangement and telomeric microdeletion in a patient with Raine syndrome and subsequently identified mutations in the FAM20C gene, located within the deleted region, in six additional Raine syndrome cases. The phenotype of Raine syndrome in the cases examined was remarkably consistent with generalized osteosclerosis of all bones, periosteal bone formation, characteristic facial phenotype and lethal within the first few weeks of life. In the current study, we have identified two unrelated individuals who presented at birth with a sclerosing bone dysplasia with features very similar to those in Raine syndrome but who survived infancy and are now aged 8 and 11 years, respectively. Mutations in FAM20C, consistent with autosomal recessive inheritance, were identified in both cases. In the first case, a homozygous non-synonymous mutation in exon 7 (1309G>A D437N) was identified, and in the second case, compound heterozygosity for non-synonymous mutations in exon 2 (731T>A I244N) and in exon 3 (796G>A G266R) was revealed. Raine syndrome has been previously considered to be a neonatal lethal condition. However, the identification of mutations in these two patients confirms a broader phenotypic spectrum and that mutation of FAM20C does not always lead to the infantile lethality previously seen as a prerequisite for Raine syndrome diagnosis.
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