The time of onset of abnormal calcification in spondylometaepiphyseal dysplasia, short limb-abnormal calcification type

Abstract

A 1-month-old boy with shortness of extremities on prenatal US was referred to our department with a provisional diagnosis of achondroplasia. His height was normal but he had short extremities and platyspondyly, premature carpal epiphyses on both hands, and short tubular bones with irregular metaphyses on radiographs. Re-evaluation of the patient at the age of 1 year revealed very short height and premature calcification of the costal cartilages and epiphyses. Spondylometaepiphyseal dysplasia (SMED), short limb-abnormal calcification type was diagnosed. This condition is a very rare autosomal recessively inherited disorder, and most of the patients die in early childhood due to neurological involvement. At the age of 2 years and 5 months, a CT scan showed narrowing of the cervical spinal canal. One month later he died suddenly because of spinal cord injury. In conclusion early diagnosis is very important because the recurrence risk is high and patients may die due to early neurological complications. The time of onset of abnormal calcifications, a diagnostic finding of the disease, is at the age of around 1 year in most patients. When abnormal calcifications are not yet present, but radiological changes associated with SMED are present, this rare disease must be considered.

Mutations in DDR2 Gene Cause SMED with Short Limbs and Abnormal Calcifications

“…6 The reduced chondrocyte proliferation and bone growth found in the ddr2 À/À mouse was compatible with the previously reported extremely abnormal cartilage documented at the costochondral junction of one SMED-SL patient. 1,5,6 The DDR2 gene is a member of the receptor tyrosine kinase [RTK] family and is involved in signal transduction. 10,11 The DDR2 protein consists of an extracellular discoidin domain and a cytosolic tyrosine kinase domain (TK).…”

Spondylometaepiphyseal Dysplasia Short Limb-Abnormal Calcification Type in Turkish Patients Reveals a Novel Mutation and New Features

“…Our third case was reported previously with his clinical findings by Tüysüz et al [2009]. The boy was from Northern Anatolia.…”

“…In this study, we present 2 new cases with one of them harbouring a novel variant. In addition, we reviewed a previously reported case by Tüysüz et al [2009] who was found to harbour the same identified truncating pathogenic variant of the other recently reported Turkish child reported by Ürel-Demir et al [2018]. We defined the course and features of this disorder in Turkish patients.…”

“…DOI: 10.1159/000517848 SMED-SL/AC has been observed mainly in Middle Eastern and Puerto Rican communities. So far 37 cases have been reported [Borochowitz et al, 1993;Al-Gazali et al, 1996;Fano et al, 2001;Bargal et al, 2009;Dias et al, 2009;Smithson et al, 2009;Tüysüz et al, 2009;Ali et al, 2010;Rozovsky et al, 2011;Al-Kindi et al, 2014;Mansouri et al, 2016;Ürel-Demir et al, 2018]. It is usually a severe condition which may be fatal due to atlantoaxial instability and spinal cord compression or recurrent bronchopulmonary infections [Langer et al, 1993;Al-Gazali et al, 1996].…”

Report of a Novel Homozygous Nonsense DDR2 Mutation in an Indian Adult Male with Spondylo-meta-epiphyseal Dysplasia, Short Limb-Abnormal Calcification Type

“…Prenatal ultrasound showing short extremities has been reported in literature. 11 The early manifestations of the condition, along with the use of exome sequencing, permit an early conformation of diagnosis. This will allow for early surveillance for known complications, such as cord compression.…”