Genetic analysis and serum level of cartilage oligomeric matrix protein in patients with pseudoachondroplasia.
BACKGROUND
Pseudoachondroplasia (PSACH) is an autosomal-dominant osteochondrodysplasia due to mutations in the gene encoding cartilage oligomeric matrix protein (COMP). Clinical diagnosis of PSACH is based primarily on family history, physical examination, and radiographic evaluation. There is evidence that decreased serum COMP concentration may serve as a diagnostic marker in PSACH. Here, we investigated the role of this gene and the serum COMP concentration in Chinese patients with PSACH.


METHODS
A family with three patients and a sporadic case were recruited. Genomic and phenotypic data were recorded. The diagnosis of PSACH was made on the base of clinical evaluation. The genomic DNA was extracted from peripheral blood leukocytes. The 8-19 exons and flanking intron-exon boundary sequences of COMP were amplified by polymerase chain reaction (PCR) and screened for mutation by direct DNA sequencing. Serum COMP concentrations of 4 patients and age-compatible control group of 20 unrelated healthy subjects were analyzed on the basis of an ELISA Kit for human cartilage oligomeric matrix protein.


RESULTS
A deletion (c.1447-1455del) was identified in exon 13 in the sporadic case. The mean serum COMP concentrations of four patients (3.12+/-2.28) were significantly lower than those of control group (10.86+/-2.21, P<0.05). There was no overlap in the distribution of serum COMP concentration between PSACH patients and controls.


CONCLUSIONS
Mutations in COMP gene are responsible for the PSACH. Serum COMP concentration may be suggested as an additional diagnostic marker to aid clinical findings in suspected cases of PSACH.
Liu
Feng-xia
FX
Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Peking Union Medical College Hospital, Department of Rheumatology, WHO Collaborating Centre for Community Control of Hereditary Diseases, Beijing 100730, China.
Li
Zhi-ling
ZL
Wei
Zhen-ji
ZJ
Meng
Yan
Y
Ren
Cui-ai
CA
Zhang
Xu-de
XD
Yu
Meng-xue
MX
Huang
Shang-zhi
SZ
D064236:Cartilage Oligomeric Matrix Protein; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005091:Exons / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000097:blood* / Q000235:genetics*; D005260:Female; D006023:Glycoproteins / Q000097:blood* / Q000235:genetics*; D006801:Humans; D008297:Male; D064235:Matrilin Proteins; D009154:Mutation; D010009:Osteochondrodysplasias / Q000097:blood* / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction
D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; C577553:TSP5 protein, human