CLINICAL VARIABILITY IN TWO SISTERS WITH KEUTEL SYNDROME DUE TO A HOMOZYGOUS MUTATION IN MGP GENE

Abstract

Clinical variability in two sisters with Keutel syndrome due to a homozygous mutation in MGP gene: Keutel syndrome (KS) is an autosomal recessive disease characterised by abnormal cartilage calcification, brachytelephalangism, peripheral pulmonary artery stenosis, hearing loss and midface retrusion. KS is caused by homozygous mutations in MGP, a gene encoding Matrix Gla protein which acts as a calcification inhibitor in extracellular matrix. We present two Turkish sisters (22 and 13 years old) who had abnormal cartilage calcification, brachytelephalangism, congenital heart defect and chronic asthmatic bronchitis. The patients were homozygous for c.62-2A>G (IVS1-2 A>G) mutation in MGP gene. Abnormal cartilage calcification, brachytelephalangism and midfacial retrusion are the hallmarks of KS. It was observed that the younger sister had striking cartilaginous calcifications, midfacial retrusion and severe brachytelephalangism while her older sister had mild costal cartilaginous calcifications and brachytelephalangism without any midfacial retrusion. Intrafamiliar clinical variability for KS has not been described previously.