ABSTRACT
Arthrogryposis multiplex congenita (AMC) is an important birth defect with a significant genetic contribution. Many syndromic forms of AMC have been described, but remain unsolved at the molecular level. In this report, we describe a novel syndromic form of AMC in two multiplex consanguineous families from Saudi Arabia and Oman. The phenotype is highly consistent, and comprises neurogenic arthrogryposis, microcephaly, brain malformation (absent corpus callosum), optic atrophy, limb fractures, profound global developmental delay, and early lethality. Whole-exome sequencing revealed a different homozygous truncating variant in SCYL2 in each of the two families. SCYL2 is a component of clathrin-coated vesicles, and deficiency of its mouse ortholog results in a severe neurological phenotype that largely recapitulates the phenotype observed in our patients. Our results suggest that severe neurogenic arthrogryposis with brain malformation is the human phenotypic consequence of SCYL2 loss of function mutations.
Subject(s)
Arthrogryposis , Genes, Recessive , Loss of Function Mutation , Pedigree , Protein Serine-Threonine Kinases/genetics , Adult , Arthrogryposis/diagnostic imaging , Arthrogryposis/genetics , Arthrogryposis/pathology , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , SyndromeABSTRACT
We report on a case of Raine syndrome with a mutation in FAM20C and typical phenotypic features consisting of midface hypoplasia, hypoplastic nose, choanal atresia, wide fontanelle, exophthalmos, generalized osteosclerosis and intracranial calcification. New features in our patient are cerebellar hypoplasia and pachygyria. We review the literature and conclude that the triad of hypoplastic nose, exophthalmos and generalized osteosclerosis and/or intracranial calcification is consistent in all molecularly confirmed cases.