A Novel COMP Gene Mutation in a Korean Kindred with Multiple Epiphyseal Dysplasia

Multiple epiphyseal dysplasia (MED) is a clinically and genetically heterogeneous chondroplasia, characterized by delayed development of the ossification centers and, deformities of the extremities that involve only the epiphysis and result in mild short stature. Mutations in the cartilage oligomeric matrix protein (COMP) gene are most commonly found, and most of the mutations are located in the calmodulin-like repeats and the C-terminal domain. We report a Korean kindred of?12 family members with MED in four generations who were found to have a novel mutation in the COMP gene. A pedigree showed early onset osteoarthritis requiring arthroplasty that was an autosomal dominant inherited trait. Radiological examinations demonstrated the presence of osteochondral defects in the medial femoral condyles, and the knee and hip joints showed variable degrees of precocious degenerative changes. Mutation analysis of the COMP gene in the proband and five other affected family members identified a novel missense mutation, c.1280G>C (p.Gly427Ala) in exon 12, which was not found in three unaffected family members. Direct sequencing of the COMP gene may yield pathogenic mutations in dominantly inherited MED cases, and may provide opportunities of carrier detection among high-risk family members, leading to genetic counseling for early diagnosis and intervention before the onset of complications.

The spectrum of 5p deletion in Korean 20 patients with Cri du chat syndrome

PURPOSE: Cri-du-Chat syndrome (CdCs) is a rare but clinically recongnizable condition with an estimated incidence of 1:50,000 live births. The clinical characteristics of the syndrome include severe psychomotor and mental retardation, microcephaly, hypertelorism, hypotonia, and slow growth. Also the size of the chromosome 5p deletion ranges were known from the region 5p13 to the terminal region. In this study, we report the spectrum of 5p deletion in Korean 20 pts. with CdCs and genotype-phenotype associations in CdCs. METHODS: In order to delineate genotype-phenotype correlation, molecular cytogenetic studies including GTG banding and clinical characterization were performed on Korean 20 pts with CdCs including parents. CGH array and Fluorescence in situ hybridization (FISH) analysis were used to confirm a terminal deletion karyotype and map more precisely the location of the deletion breakpoint. RESULTS: Molecular analysis of the spectrum of 5p deletion revealed 9 pts (45%) with a del (5)(p14), 7 pts. (35%) a del (5)(p13), 3 pts. (15%) a del (5)(p15.1) and 1 pt. (5%) a del (5)(p15.2) in 20 pts with CdCs. 4(20%)pts were identified to have additional chromosome abnormalites of deficiency and duplication involving chromosomes of 6, 8, 18, & 22. Parental study identified 3 familial case (2 paternal and 1 maternal origin) showing parents being a balanced translocation carrier. And the comparison study of the deletion break points among these 20 pts. with their phenotype has showed the varying clinical pheno-types in the CdCs critical region. CONCLUSION: The characterization of 5p deletion including parental study may help to delineate the genotypephenotype correlation in CdCs. Also these molecular cytogenetic analyses will be able to offer better information for accurate genetic diagnosis in CdCs and further make possible useful genetic counseling in pts. and family.