Molecular genetics of 3beta-hydroxy-Delta5-C27-steroid oxidoreductase deficiency in 16 patients with loss of bile acid synthesis and liver disease.
The 3beta-hydroxy-Delta(5)-C(27)-steroid oxidoreductase (C(27) 3beta-HSD) is a membrane-bound enzyme of the endoplasmic reticulum that catalyzes an early step in the synthesis of bile acids from cholesterol. Subjects with autosomal recessive mutations in the encoding gene, HSD3B7, on chromosome 16p11.2-12 fail to synthesize bile acids and develop a form of progressive liver disease characterized by cholestatic jaundice and malabsorption of lipids and lipid-soluble vitamins from the gastrointestinal tract. The gene encoding the human C(27) 3beta-HSD enzyme was isolated previously, and a 2-bp deletion in exon 6 of HSD3B7 was identified in a well characterized subject with this disorder. Here, we report a molecular analysis of 15 additional patients from 13 kindreds with C(27) 3beta-HSD deficiency. Twelve different mutations were identified in the HSD3B7 gene on chromosome 16p11.2-12. Ten mutations were studied in detail and shown to cause complete loss of enzyme activity and, in two cases, alterations in the size or amount of the transcribed mRNA. Mutations were inherited in homozygous form in 13 subjects from 10 families and compound heterozygous form in four subjects from three families. We conclude that a diverse spectrum of mutations in the HSD3B7 gene underlies this rare form of neonatal cholestasis.
Cheng
Jeffrey B
JB
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9046, USA.
Jacquemin
Emmanuel
E
Gerhardt
Marie
M
Nazer
Hisham
H
Cresteil
Danièle
D
Heubi
James E
JE
Setchell
Kenneth D R
KD
Russell
David W
DW
D015096:3-Hydroxysteroid Dehydrogenases / Q000172:deficiency* / Q000235:genetics*; D000293:Adolescent; D001647:Bile Acids and Salts / Q000096:biosynthesis*; D002648:Child; D002675:Child, Preschool; D002779:Cholestasis / Q000201:enzymology / Q000235:genetics; D002885:Chromosomes, Human, Pair 16; D004064:Digestive System / Q000378:metabolism; D005091:Exons; D005260:Female; D017353:Gene Deletion; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D050356:Lipid Metabolism; D008107:Liver Diseases / Q000201:enzymology*; D008286:Malabsorption Syndromes / Q000201:enzymology / Q000235:genetics; D008297:Male; D009154:Mutation; D010375:Pedigree; D012333:RNA, Messenger / Q000032:analysis; D014815:Vitamins / Q000378:metabolism
D001647:Bile Acids and Salts; D012333:RNA, Messenger; D014815:Vitamins; D015096:3-Hydroxysteroid Dehydrogenases