mosaic SMO syndrome

Rare Disease

MONDO:1030005

Definition

A somatic mosaic condition caused by a postzygotic mutation (c.1234 C>T p.Leu412Phe) in the SMO gene. Two overlapping clinical syndromes associated with this variant in SMO have been reported; Curry-Jones Syndrome (MIM:601707) and Happle-Tinschert Syndrome. The syndrome is characterized by cutaneous and skeletal manifestations such as linear hypo‐ or hyperpigmented lesions, basaloid follicular hamartomas, palmoplantar pitting, atrophoderma, hypertrichosis, polydactyly or syndactyly, rib anomalies (rudimentary ribs), and limb‐length anomalies. Craniofacial and dental abnormalities such as dysmorphic facies, macrocephaly, craniosynostosis, jaw tumors (ameloblastoma) have also been reported. Additional abnormalities impacting the gastrointestinal, cerebral, ophthalmic, and gonadal organs should also be considered. Some of these features include anal anomaly, colonic adenocarcinoma, severe constipation, myelofibrosis and smooth muscle hamartomas, malrotation, medulloblastoma, cerebral malformations, developmental delay, cataract, microphthalmia, coloboma, glaucoma, and cryptorchidism.