High allele frequency of the p.Q258X mutation and identification of a novel mis-splicing mutation in the STAR gene in Korean patients with congenital lipoid adrenal hyperplasia

• Published in: European journal of endocrinology Vol. 165; no. 5; pp. 771 - 778
• Main Authors: Kim, Jae-Min, Choi, Jin-Ho, Lee, Jung Hyun, Kim, Gu-Hwan, Lee, Beom Hee, Kim, Hae Soon, Shin, Jeh-Hoon, Shin, Choong-Ho, Kim, Chan Jong, Yu, Jeesuk, Lee, Dae-Yeol, Cho, Won Kyoung, Suh, Byung-Kyu, Lee, Ji Eun, Chung, Hye Rim, Yoo, Han-Wook
• Format: Journal Article
• Language: English
• Published: Bristol BioScientifica 01-11-2011; European Society of Endocrinology
• Subjects: 46, XY Disorders of Sex Development - epidemiology; 46, XY Disorders of Sex Development - genetics; Adolescent; Adrenal Hyperplasia, Congenital - epidemiology; Adrenal Hyperplasia, Congenital - genetics; Adrenals. Adrenal axis. Renin-angiotensin system (diseases); Alternative splicing; Alternative Splicing - genetics; Animals; Asian Continental Ancestry Group - genetics; Biological and medical sciences; Cercopithecus aethiops; Child; Child, Preschool; Cholesterol; Clinical Study; COS Cells; DNA; Endocrinopathies; Exons; Expression vectors; Female; Fundamental and applied biological sciences. Psychology; Gene frequency; Gene Frequency - genetics; genomics; Humans; Hyperplasia; Infant; Introns; Korea - epidemiology; Male; Medical sciences; Mutation; Mutation - genetics; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Phosphoproteins - genetics; Pregnenolone; Site-directed mutagenesis; Star protein; Steroidogenesis; Steroidogenic acute regulatory protein; Transcription; Vertebrates: endocrinology; Asia; Korea; Endocrinopathy; Human; Adrenal cortex diseases; Splicing; Korean; Patient; Hyperadrenocorticism; Identification; Enzymopathy; Congenital adrenal hyperplasia syndrome; Allele; Gene; Adrenal gland diseases; Frequency; Genetics; Mutation; High frequency; Endocrinology
• ISSN: 0804-4643; 1479-683X
• DOI: 10.1530/EJE-11-0597

ObjectiveSteroidogenic acute regulatory (STAR) protein plays a crucial role in steroidogenesis, and mutations in the STAR gene cause congenital lipoid adrenal hyperplasia (CLAH). This study investigated the STAR mutation spectrum and functionally analyzed a novel STAR mutation in Korean patients with CLAH.MethodsMutation analysis of STAR was carried out in 25 unrelated Korean CLAH patients. A region of STAR comprising exons 4–7 was cloned from human genomic DNA into an expression vector, followed by site-directed mutagenesis and transient expression in COS7 cells. The splicing pattern was analyzed by in vitro transcription, and each transcript was functionally characterized by measuring pregnenolone production in COS7 cells cotransfected with the cholesterol side chain cleavage system.ResultsMutation p.Q258X was identified in 46 of 50 alleles (92%); mutation c.653C>T was detected in two alleles (4%); and mutations p.R182H and c.745–6_810del were found in one allele (2%). Reverse transcriptase-PCR products amplified from a patient heterozygous for compound c.653C>T and c.745–6_810del mutation revealed multiple alternatively spliced mRNAs. In vitro expression analysis of a minigene consisting of exons 4–7 containing the c.653C>T yielded two transcripts in which exon 6 or exons 5 and 6 were skipped. The encoded proteins exhibited defective pregnenolone-producing ability. The c.745–6_810del mutation led to full and partial intron retention.Conclusionsp.Q258X is the most common STAR mutation in Korea. A previously reported c.653C>T variant was found to cause aberrant splicing at the mRNA level, resulting in perturbation of STAR function. The c.745–6_810del mutation also resulted in aberrant splicing.