Mutation analysis of steroid acute regulatory protein gene in a patient affected with congenital lipoid adrenal hyperplasia

Abstract

Objective To analyze the clinical characteristic s of an infant with congenital lipoid adrenal hyperplasia (CLAH),and to sequence the acute regulatory protein (steroid acute regulatory,StAR) gene of the infant patient and her pedigree.Methods Physical examination,laboratory tests,and imaging examination of the 11-month-old patient with CLAH were collected.DNA was extracted from blood samples of the patient and her parents.The 7 exons of StAR gene were amplified by PCR and then sequenced.Results Dark skin,girl vulva,and one each 1.0 cm×1.0 cm palpable lump in inguinal area bilaterally were observed.The adrenocorticotropic hormone (ACTH) was 253 pg/ml,cortisol was 27.6 nmol/L at 8 am,17-hydroxyprogesterone was 3 nmol/L.Uhrasound showed that sign of testicular ultrasonography existed in bilateral inguinal regions.Karyotype analysis showed 46,XY.Sequencing of PCR amplified fragments showed that there were two heterozygous mutations c.229C ＞ T,p (Gln77X) and C.659A＞G,p (His220Arg) of StAR gene in this patient.By rectifying the disturbance of electrolyte,and treating with hydrocortisone and 9α fludrocortisone,etc,the patient has been stable so far.Conclusion The patient presents typical clinical manifestations.Two heterozygous mutations including c.229C ＞T,p (Gln77X) from maternal and C.659A＞G,p (His220Arg) from paternal of StAR gene were detected.Wherein the c.659A＞G,p.(His220Arg) as a novel point mutation of StAR gene,has not been reported so far. Key words: Congenital lipoid adrenal hyperplasia; Steroid acute regulatory protein; Sequence analysis