Gene and phenotype analysis of congenital generalized lipodystrophy in Japanese: a novel homozygous nonsense mutation in seipin gene.
Congenital generalized lipodystrophy (CGL), Berardinelli-Seip syndrome, is a rare metabolic disorder characterized by a near total lack of adipose tissue from birth or early infancy. Recently, seipin, encoding a 398-amino acid protein of unknown function, and AGPAT2, encoding 1-acyl-sn-glycerol-3-phosphate acyltransferase 2, were identified as causative genes for CGL. Seipin mutations were found in patients from families originating from Europe and the Middle East. AGPAT2 mutations were found predominantly in African ancestry. However, no information is available on these genes in the pathogenesis of CGL in Asian ancestry. We examined the sequences of the entire coding region of seipin and AGPAT2 in four Japanese CGL patients from independent families. Their average body fat content was 4.7 +/- 0.5%, and the plasma leptin level was 1.15 +/- 0.14 ng/ml. We identified a novel nonsense mutation of seipin at codon 275 (R275X). Of four CGL patients, three were homozygous for R275X. No seipin mutation was found in any exon in one patient. We did not find any AGPAT2 mutations in our Japanese patients, suggesting that AGPAT2 is a minor causative gene, if any, for CGL in Japanese. This is the first report on gene and phenotype analysis of CGL in Japanese.
Ebihara
Ken
K
Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan. kebihara@kuhp.kyoto-u.ac.jp
Kusakabe
Toru
T
Masuzaki
Hiroaki
H
Kobayashi
Nozomi
N
Tanaka
Tomohiro
T
Chusho
Hideki
H
Miyanaga
Fumiko
F
Miyazawa
Takashi
T
Hayashi
Tatsuya
T
Hosoda
Kiminori
K
Ogawa
Yoshihiro
Y
Nakao
Kazuwa
K
D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D003062:Codon; D018389:Codon, Nonsense; D005260:Female; D044388:GTP-Binding Protein gamma Subunits / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008060:Lipodystrophy / Q000151:congenital* / Q000175:diagnosis / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D010375:Pedigree; D010641:Phenotype
C432679:BSCL2 protein, human; D003062:Codon; D018389:Codon, Nonsense; D044388:GTP-Binding Protein gamma Subunits