Obstructive sleep apnea and twins.

PURPOSE: Present an intriguing case of a man suffering of OSA who has a homozygous monochorionic twin. Made a systematic review of the literature to summarize existing data and the reported incidence of OSA in twins.

METHODS

Case presentation and systematic literature review, according to the PRISMA guidelines about twins and Obstructive sleep Apnea.

RESULTS

Our patient had a severe OSA condition with an Apnea Hypopnea index (AHI) of 57.6. This patient had a twin who did not suffer from sleep apnea and presented different oropharyngeal and endoscopic anatomical characteristics. Six eligible studies were identified investigating OSA or OSA-related traits in twins. All studies demonstrated higher concordance among monozygotic than dizygotic twins and substantial heritability estimates (40%-83%), particularly for AHI and ODI. However, non-shared environmental and anatomical factors accounted for considerable phenotypic variability.

CONCLUSION

Despite the genetic factors related to the sleep apnea, differences in anatomical features and lifestyle could contributed to the different expression of OSA.