Missense variant in CCDC22 causes X-linked recessive intellectual disability with features of Ritscher-Schinzel/3C syndrome.

Ritscher-Schinzel syndrome (RSS)/3C (cranio-cerebro-cardiac) syndrome (OMIM#220210) is a rare and clinically heterogeneous developmental disorder characterized by intellectual disability, cerebellar brain malformations, congenital heart defects, and craniofacial abnormalities. A recent study of a Canadian cohort identified homozygous sequence variants in the KIAA0196 gene, which encodes the WASH complex subunit strumpellin, as a cause for a form of RSS/3C syndrome. We have searched for genetic causes of a phenotype similar to RSS/3C syndrome in an Austrian family with two affected sons.

Severe congenital cutis laxa with cardiovascular manifestations due to homozygous deletions in ALDH18A1.

Autosomal recessive cutis laxa (ARCL) type 2 constitutes a heterogeneous group of diseases mainly characterized by lax and wrinkled skin, skeletal anomalies, and a variable degree of intellectual disability. ALDH18A1-related ARCL is the most severe form within this disease spectrum. Here we report on the clinical and molecular findings of two affected individuals from two unrelated families.

ClC-7 expression levels critically regulate bone turnover, but not gastric acid secretion.

Mutations in the 2Cl(-)/1H(+)-exchanger ClC-7 impair osteoclast function and cause different types of osteoclast-rich osteopetrosis. However, it is unknown to what extent ClC-7 function has to be reduced to become rate-limiting for bone resorption. In osteoclasts from osteopetrosis patients expression of the mutated ClC-7 protein did not correlate with disease severity and resorption impairment.

Genotype-phenotype spectrum of PYCR1-related autosomal recessive cutis laxa.

Autosomal recessive cutis laxa type 2B (ARCL2B; OMIM # 612940) is a segmental progeroid disorder caused by mutations in PYCR1 encoding pyrroline-5-carboxylate reductase 1, which is part of the conserved proline de novo synthesis pathway. Here we describe 33 patients with PYCR1-related ARCL from 27 families with initial diagnoses varying between wrinkly skin syndrome, gerodermia osteodysplastica, De Barsy syndrome or more severe progeria syndromes. Given the difficult differential diagnosis of ARCL syndromes we performed a systematic comparison of clinical features of PYCR1-related ARCL.