New cause for BOS?

Researchers have expanded the clinical spectrum of KLHL7 […] by describing a syndrome with features overlapping CS/CISS1 (Crisponi syndrome/cold-induced sweating syndrome type 1) and Bohring-Opitz Syndrome (BOS). At six patients with microcephaly, facial dysmorphism, including exophthalmos, nevus flammeus of the glabella and joint contractures with a suspected BOS posture in five out of six patients they found with whole-exome sequencing (WES) mutations in the KLHL7 gene.

Prior to 2011, geneticists relied on making a clinical diagnosis by recognizing the distinguishable physical characteristics in the appearance of their patients. In 2011, researchers at the Radboud University Nijmegen medical centre discovered one genetic cause of Bohring-Opitz Syndrome. They found that seven of 13 examined patients with the BOS phenotype had the novo mutation in the ASXL1 gene. However another six children with clinical diagnosis of BOS didn’t have this mutation, this indicates that other genes may be involved in this syndrome suggesting clinical and genetic heterogeneity, meaning there must be at least one other cause of BOS.

»Bruel A, Bigoni S, Kennedy J, et al: Expanding the clinical spectrum of recessive truncating mutations of KLHL7 to a Bohring-Opitz-like phenotype.