The authors reported eight loss-of-function and two missense variants in BPTF. The BPTF variants were found in unrelated individuals aged between 2.1 and 13 years, who manifested variable degrees of developmental delay/intellectual disability (10/10), speech delay (10/10), postnatal microcephaly (7/9), and dysmorphic features (9/10).
The authors reported five individuals with two recurrent de novo missense mutations in RAB11B. An overlapping neurodevelopmental phenotype, including severe intellectual disability with absent speech, epilepsy, and hypotonia was observed in all affected individuals. Additionally, visual problems, musculoskeletal abnormalities, and microcephaly were present in the majority of cases. Re-evaluation of brain MRI images of four individuals showed a shared distinct brain phenotype, consisting of abnormal white matter (severely decreased volume and abnormal signal), thin corpus callosum, cerebellar vermis hypoplasia, optic nerve hypoplasia and mild ventriculomegaly.
The authors identified six different de novo missense mutations in DHX30 in twelve unrelated individuals. Patients were affected by global developmental delay, intellectual disability, severe speech impairment and gait abnormalities.
The authors reported two siblings with biallelic loss-of-function variants in DOCK3. Common features in both affected individuals included severe developmental disability, ataxic gait, and severe hypotonia.
The authors reported biallelic mutations in GPAA1 in ten individuals from five families. Using whole-exome sequencing, they identified two frameshift mutations, one intronic splicing mutation and six missense mutations. Most individuals presented with global developmental delay, hypotonia, early-onset seizures, cerebellar atrophy, and osteopenia.
The authors reported on eight subjects from four independent families affected by auditory neuropathy and optic atrophy. Whole-exome sequencing revealed biallelic mutations in FDXR in affected subjects of each family.
The authors identified and characterised CLDN10 mutations in two patients with a hypokalemic-alkalotic salt-losing nephropathy. The first patient was diagnosed with Bartter syndrome (BS) >30 years ago. At re-evaluation, the authors observed hypocalciuria and hypercalcemia, suggesting Gitelman syndrome (GS). However, serum magnesium was in the upper normal to hypermagnesemic range, thiazide responsiveness was not blunted, and genetic analyses did not show mutations in genes associated with GS or BS. Whole-exome sequencing revealed compound heterozygous CLDN10 sequence variants. The patient had reduced urinary concentrating ability, with a preserved aquaporin-2 response to desmopressin and an intact response to furosemide. These findings were not in line with any other known salt-losing nephropathy. Subsequently, the authors identified a second unrelated patient showing a similar phenotype, presenting a compound heterozygous CLDN10 sequence variants.
The authors described two foetuses with a unique pattern of multiple congenital anomalies, including a diaphragmatic hernia, short bowel and asplenia, born to first-cousin parents. Whole exome sequencing showed that both were homozygous for a missense variant in HLX1 gene.
GeneReviews are expert-authored, peer-reviewed disease descriptions ("chapters") presented in a standardised format and focused on clinically relevant and medically actionable information on the diagnosis, management, and genetic counselling of patients and families with specific inherited conditions.
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