Cranio-lenticulo-sutural dysplasia

Cranio-lenticulo-sutural dysplasia, also called Boyadjiev-Jabs syndrome, is a disease of infancy caused by a disorder on chromosome 14, inherited in an autosomal recessive pattern that requires a faulty copy of the gene from each parent. It results from a missense mutation in the SEC23A gene at chromosome 14q13-q21, in which the amino acid phenylalanine is mistakenly replaced by leucine, producing a non-functional SEC23A protein; because SEC23A is needed for the COPII pathway that exports proteins from cells, the defect prevents vesicles from properly leaving the endoplasmic reticulum for the Golgi apparatus, so collagen and other secreted proteins build up abnormally and impair bone formation and craniofacial development. Symptoms appear in infancy and include Y-shaped cataracts, skeletal defects, reduced mineralization of the skull, facial abnormalities and delayed motor development, among other features affecting bone structure.