A novel variant site of Alstrom syndrome in a Chinese child: a case report

Abstract

Background: Alstrom syndrome (ALMS) is an ultra-rare multisystem genetic disorder caused by autosomal recessive inheritance of the ALMS1 gene. It manifests as multisystem dysfunction, displaying unique clinical signs and symptoms and various severity, which may lead to delayed prognosis or misdiagnosis in medical practice. Although almost 300 pathogenic variants have been reported, there are some variant sites that have not been recognized yet.Case Description: We report a case of a 14-year-old boy with manifestations, including binocular vision loss, acanthosis nigricans, type 2 diabetes, insulin resistance, elevated transaminase, hepatic fibrosis, and proteinuria. Compound heterozygous variants in the ALMS1 gene have been discovered by whole exon sequencing. One of his variant sites was C. 8158C>T, which was from his father. And the other variant site was C. 3575C>A, which was from his mother. To the great of our knowledge, this site has not been reported before. Both of the variants make the synthesis of the peptide chain terminated in advance and an incomplete polypeptide chain is formed. Conclusions:The clinical presentations of ALMS are complicated and varied. Although early diagnosis can be made according to typical clinical symptoms, whole exon sequencing is necessary for the diagnosis of ALMS, as indicated by our study.

Unique phenotypic–genotypic correlation in Saudi patients with ALMS1 mutations

“…Moreover, this variant has recently been identified in a Chinese patient who showed the full clinical spectrum of Alström syndrome. [ 3 ]…”

Acanthosis Nigricans: Pointer of Endocrine Entities

“…Currently, insulin resistance (IR) represents an endocrine/metabolic issue with a high prevalence in the general population, frequently associated with conditions such as obesity, diabetes mellitus (DM), dyslipidemia-like hypertriglyceridemia, metabolic syndrome (MS), hepatic steatosis, polycystic ovary syndrome (PCOS), or, rarely, some endocrine tumors [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Rare IR-related entities include different types of congenital or acquired lipodystrophy syndromes (Berardinelli–Seip syndrome), mutations of insulin receptors (type A IR syndrome, leprechaunism or Donohue syndrome, and Rabson–Mendenhall syndrome), or other genetic disorders such as Alstrom syndrome, SOFT syndrome, MARFAN syndrome, and monogenetic obesity with underlying melanocortin-4 receptor ( MC4R ) gene mutations [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”