A novel mutation L260P of the steroidogenic acute regulatory protein gene in three unrelated patients of Swiss ancestry with congenital lipoid adrenal hyperplasia.
BACKGROUND
Lipoid congenital adrenal hyperplasia (CAH) is the most severe form of CAH leading to impaired production of all adrenal and gonadal steroids. Mutations in the gene encoding steroidogenic acute regulatory protein (StAR) cause lipoid CAH.


OBJECTIVE
We investigated three unrelated patients of Swiss ancestry who all carried novel mutations in the StAR gene. All three subjects were phenotypic females with absent Müllerian derivatives, 46,XY karyotype, and presented with adrenal failure.


RESULTS
StAR gene analysis showed that one patient was homozygous and the other two were heterozygous for the novel missense mutation L260P. Of the heterozygote patients, one carried the novel missense mutation L157P and one had a novel frameshift mutation (629-630delCT) on the second allele. The functional ability of all three StAR mutations to promote pregnenolone production was severely attenuated in COS-1 cells transfected with the cholesterol side-chain cleavage system and mutant vs. wild-type StAR expression vectors.


CONCLUSIONS
These cases highlight the importance of StAR-dependent steroidogenesis during fetal development and early infancy; expand the geographic distribution of this condition; and finally establish a new, prevalent StAR mutation (L260P) for the Swiss population.
Biochimie Endocrinienne et Moléculaire, Hopital Debrousse, 29 Rue Soeur Bouvier, F-69322 Lyon Cedex 05, France. morel@lyon.inserm.fr.
Christa E
CE
Flück
Alexander
A
Maret
Delphine
D
Mallet
Stéphanie
S
Portrat-Doyen
John C
JC
Achermann
Bruno
B
Leheup
Gérald E
GE
Theintz
Primus E
PE
Mullis
Yves
Y
Morel
D000312:Adrenal Hyperplasia, Congenital / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007223:Infant; D007930:Leucine; D018895:Microsatellite Repeats; D020125:Mutation, Missense; D010375:Pedigree; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D011284:Pregnenolone / Q000096:biosynthesis; D011392:Proline; D013557:Switzerland; D000098682:Steroidogenic Acute Regulatory Protein
D010750:Phosphoproteins; D000098682:Steroidogenic Acute Regulatory Protein; D011284:Pregnenolone; D011392:Proline; D007930:Leucine