Phenotypic expressions of a Gly 154Arg mutation in type II collagen in two unrelated patients with spondyloepimetaphyseal dysplasia (SEMD).
Type II collagenopathies consist of chondrodysplasias ranging from lethal to mild in severity. A large number of mutations has been found in the COL2A1 gene. Glycine substitutions have been the most common types of mutation. Genotype-phenotype correlations in type II collagenopathies have not been established, partly because of insufficient clinical and radiographic description of the patients. We found a glycine-to-arginine substitution at position 154 in type II collagen in two unrelated isolated propositi with spondyloepimetaphyseal dysplasia and provide a comparative clinical and radiographic analysis from birth to young adulthood for this condition. The clinical phenotype was disproportionate short stature with varus/valgus deformities of the lower limbs requiring corrective osteotomies, and lumbar lordosis. The skeletal radiographs showed an evolution from short tubular bones, delayed epiphyseal development, and mild vertebral involvement to severe metaphyseal dysplasia with dappling irregularities, and hip "dysplasia." The metaphyseal abnormalities disappeared by adulthood.
Kaitila
I
I
Department Clinical Genetics, Helsinki University Hospital, Finland.
Körkkö
J
J
Marttinen
E
E
Ala-Kokko
L
L
D000328:Adult; D000375:Aging; D000595:Amino Acid Sequence; D001120:Arginine; D001483:Base Sequence; D001846:Bone Development; D001842:Bone and Bones / Q000000981:diagnostic imaging; D003094:Collagen / Q000235:genetics*; D005260:Female; D005838:Genotype; D005998:Glycine; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D010009:Osteochondrodysplasias / Q000145:classification / Q000235:genetics* / Q000503:physiopathology; D010375:Pedigree; D010641:Phenotype; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011859:Radiography; D013131:Spine / Q000000981:diagnostic imaging
D003094:Collagen; D001120:Arginine; D005998:Glycine