Whole-exome sequencing establishes a diagnosis of Alstrom syndrome: a case report

Alström Syndrome: A Rare Cause of Severe Insulin Resistance

Diabetes mellitus is one of the most common diseases worldwide and is a major cause of morbidity and mortality. Type 2 diabetes, with its hallmark being insulin resistance, constitutes the majority of cases. Although usually related to modifiable risk factors, insulin resistance can have genetic causes. Here, we present one of the rare causes of insulin resistance. A 21-year-old man, who was deaf and blind, presented with a 3-week history of polyuria and polydipsia. He was found to have significant hyperglycemia, managed initially with insulin infusion, then he was transitioned to subcutaneous injections. Because he required high doses of insulin and had acanthosis nigricans, insulin resistance was suspected. Putting together his insulin resistance and chronic history of syndromic features, Alström syndrome was considered. Genetic testing revealed a mutation in the ALMS1 gene. The patient was then started on insulin sensitizers with a tapering of insulin with good response. Insulin resistance should be suspected if the insulin requirement is high and if acanthosis nigricans is present. Alström syndrome is a rare causes of insulin resistance. Affected individuals will usually have insulin-resistant diabetes by a young age and associated blindness and deafness. Insulin sensitizers are an important part of the treatment.

Associations of peroxisome proliferator-activated receptor-γ Pro12Ala polymorphism with non-alcoholic fatty liver disease: A meta-analysis

BACKGROUND

Polymorphisms in peroxisome proliferator-activated receptor-γ pro12Ala (PPAR-γ Pro12Ala) have been associated with Non-alcoholic Fatty Liver Disease (NAFLD) in several studies. However, the results of these studies are not entirely consistent. Thus, we performed a meta-analysis to investigate the association between the PPAR-γ Pro12Ala polymorphisms and NAFLD.

METHODS

Studies were identified by searching PubMed database and manual assessment of the cited references in the retrieved articles. Study-specific relative risks (RRs) and 95 % confidence intervals (CIs) were estimated using a random-effect model. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Relevant medical researches show that 11 studies have been conducted on the analysis of NAFLD for meta-analysis, with a total of 2404 cases and 3959 participating controls. Meta-analysis results show that PPAR-γ Pro12Ala polymorphism and NALAD Ala alleles[no association between dominance model (OR = 0.968, 95%CI: 0.734-1.276, P = 0.815); Pro/Ala vs. Pro/Pro (OR = 0.930, 95 % CI: 0.701-1.233, P = 0.612); Ala/Ala vs. Pro/Pro (OR = 1.220, 95 % CI: 0.668-2.230, P = 0.518); recessive model (OR = 0.907, 95 % CI: 0.516-1.596, P = 0.736)]. Moreover, stratification by ethnicity also revealed that no matter it is in Caucasian populations or in Asian populations, NAFLD has no association with the PPAR-γ Pro12Ala polymorphism.

CONCLUSIONS

According to the meta-analysis, both in Asians and Caucasian populations, the PPAR-γ Pro12Ala polymorphism can't be demonstrated to have any link with susceptibility to NAFLD.