Clinical and genetic findings in Alstrom syndrome: One case with obesity and acanthosis / 中华内分泌代谢杂志

ABSTRACT

Alstrom syndrome is a rare autosomal recessive multi-organ syndrome caused by variations in ALMS1 gene. We explore the underlying genetic cause in one case of Alstrom syndrome who manifasted childhood obesity, hyperinsulinemia, and acanthosis using the whole-exome sequencing, to improve clinicians′ awareness of the disease. The proband presented with obesity, acanthosis, hyperinsulinemia, and fatty liver in childhood, but without typical manifestations of Alstrom syndrome, such as retinal degeneration, hearing impairment and cardiomyopathty. Whole-exome sequencing revealed that the proband carried a complex heterozygous ALMS1 mutation, including c. 1A>T(p.M1? ) and c. 8971G>C, p. D2991H. Family verification found that his father wass heterozygous for the c. 1A>T mutation, his mother was heterozygous for the c. 8971G>C mutation, and the sister′s ALMS1 gene detection and clinical phenotype were normal, which was consistent with the autosomal recessive inheritance pattern. Through bioinformatics analysis, the new mutations c. 1A>T and c. 8971G>C in the ALMS1 gene were identified as deleterious mutations. In this study, a single case of Alstrom syndrome was reported with childhood obesity, acanthosis nigricans, and hyperinsulinemia as the main manifestations, and two new ALMSl gene mutations were discovered, which expanded the phenotype and pathogenic mutation spectrum of Alstrom syndrome.