Indian patients with CHST3-related chondrodysplasia with congenital joint dislocations.

CHST3-related chondrodysplasia with congenital joint dislocations (CDCJD, #MIM 143095), is a rare genetic skeletal disorder caused by biallelic loss of function variants in CHST3. CHST3 is critical for the sulfation of chondroitin sulfate. This study delineates the clinical presentation of nine individuals featuring the key symptoms of CDCJD; congenital joint (knee and elbow) dislocations, short trunk short stature progressive vertebral anomalies, and metacarpal shortening. Additional manifestations include irregular distal femoral epiphysis, supernumerary carpal ossification centers, bifid humerus, club foot, and cardiac abnormalities. Sanger sequencing was carried out to investigate molecular etiology in eight patients and exome sequencing in one. Genetic testing revealed five homozygous variants in CHST3 (four were novel and one was previously reported). All these variants are located on sulfotransferase domain of CHST3 protein and were classified as pathogenic/ likely pathogenic. We thus report on nine individuals with CHST3-related chondrodysplasia with congenital joint dislocations from India and suggest monitoring the health of cardiac valves in this condition.

A Novel Missense Variant in the CHST3 Underlies Spondyloepiphyseal Dysplasia with Congenital Joint Dislocations.

Background: Spondyloepiphyseal dysplasia (SED) is characterized by skeletal dysplasia and multiple joint dislocations. SEDs encompass various types, such as SED congenita, SED tarda (SED-T), SED with congenital joint dislocations (SED-CJD), SED stanescu, and SED-T with progressive arthropathy. Methods and Results: In the present study, we clinically and genetically characterized a consanguineous Pakistani family with SED-CJD. The affected member showed large joint dislocation, spinal deformities, and previously unreported facial features. Exome sequencing followed by Sanger sequencing revealed a missense variant, [c.601T>A; p.(Tyr201Asn)], in the CHST3. Conclusion: This study has not only expended the mutation spectrum in the gene CHST3 but also will facilitate diagnosis and genetic counseling of related features in the Pakistani population.

Two Somali half-siblings with CHST3-related chondrodysplasia illustrating the phenotypic spectrum and intrafamilial variability.

Deficiency of carbohydrate sulfotransferase 3 (CHST3; also known as chondroitin-6-sulfotranferase) has been associated with a phenotype of severe chondrodysplasia and progressive spinal involvement. Recent reports indicate that affected individuals initially present with neonatal multiple joint dislocations. We describe a 14-year-old Somali patient and her 3-year-old maternal half-brother with novel homozygous CHST3 mutations. The proband presented at the age 5½ years with short stature and genua valga. Her clinical course was characterized by rapid progression of spinal deformities and large joint contractures. Her half-brother presented at birth with bilateral knee dislocation and talipes equinovarus. This report of a Somali family with CHST3-related chondrodysplasia illustrates the intrafamilial variability in phenotypic expression of this rare disorder. © 2013 Wiley Periodicals, Inc.

Larsen Syndrome and Associated Spinal Deformities.

Larsen syndrome is a rare genetic disorder that affects the connective tissue within the body. The present narrative review aims to examine the genetic basis of Larsen syndrome, clarify its symptoms, and define all the existing therapeutic approaches. A comprehensive search was performed in the PubMed database. Inclusion criteria considered molecular and clinical studies, management and surgical treatment of related deformities, case reports of patients with the syndrome, reviews of the associated anomalies, articles whose full text is available in PubMed, and articles published in the English language. Larsen syndrome is caused by mutations in the FLNB gene, which encodes the cytoskeletal protein filamin B, crucial in the development of the skeleton. Symptoms include joint dislocations, characteristic facial features and anomalies of the spine. Larsen syndrome may be conservatively treated initially, although surgical intervention is usually required. Various surgical techniques, including posterior spinal fusion, anterior decompression, circumferential arthrodesis, and single-stage 360° fixation, have been proposed along with growth-sparing procedures. Preoperative and postoperative care and education ensure optimal results. Further research is needed to identify novel therapeutic modalities for this condition.

A Chinese case of CHST3-related skeletal dysplasia and a systematic review.

PURPOSE: We reported a case with carbohydrate sulfotransferase 3 (CHST3) spondyloepiphyseal dysplasia and made a systematic review of all previously reported cases. METHODS: A 14.8-year-old boy underwent clinical, radiological, and genetic evaluations. The patients and five age-matched healthy boys accepted high-resolution peripheral quantitative computed tomography evaluation. All CHST3-related skeletal dysplasia cases from PubMed and Embase were collected and summarized. The genotype-phenotype correlation was analyzed. RESULTS: The proband complained of aggravated joint pain and had a compression fracture of L2 during his second decade. Physical examination showed a height Z score of -4.94, short limbs, and restricted movement of the elbows and knees. X-rays showed carpal epiphyseal dysplasia, enlargement of elbow and knee joints, and subluxation of the left hip. Echocardiography showed abnormal cardiac valves. Compared with the norm, his total and trabecular volumetric bone mineral density (BMD), and the microarchitecture of the trabecular bone had trends to be worse at the distal radius and tibia. Two novel missense variants of c.1343T>G and c.761C>G in CHST3 were inherited from his father and mother, respectively. In the systematic review, short stature, limited joint extension, joint pain, and joint dislocation were the most common characteristics of this disorder. Height Z score and the proportion of hearing impairment had no significant differences between the missense and nonmissense mutations groups. CONCLUSION: Progressive joint pain and movement restriction are the main characteristics of CHST3-related skeletal dysplasia. BMD and bone microarchitecture of this disorder needs further exploration. There is no apparent genotype-phenotype correlation in this disorder.