Maternally inherited diabetes and deafness in a North American kindred: tips for making the diagnosis and review of unique management issues.
BACKGROUND
Mutations in mitochondrial DNA are rare etiologies of adult-onset diabetes mellitus (DM) that merit identification to 1) prevent iatrogenic lactic acidosis, 2) prompt appropriate screening of affected patients and their families, 3) provide genetic counseling, and 4) provide an opportunity to investigate strategies for preventing diabetes.


OBJECTIVE
The objective of this study is to raise awareness of this rare form of adult-onset nonobese DM so that these patients are identified and provided with appropriate care.


METHODS
We describe a kindred in which four of seven siblings have adult-onset DM and sensorineural hearing loss with a confirmed genetic mutation at position 3243 in the tRNA. Two other siblings in this kindred demonstrate different phenotypes of mitochondrial disease.


METHODS
The proband was treated with coenzyme Q10 for 1 yr.


METHODS
Outcome measures included stress thallium exercise testing and audiometry testing.


RESULTS
After 1 yr of treatment of with coenzyme Q10, repeat stress thallium testing demonstrated improvement in the exercise tolerance of the proband from 7-12 min. Audiometry testing did not demonstrate a change in the rate of hearing decline.


CONCLUSIONS
Maternally inherited diabetes and deafness is a rare cause of DM that is important to diagnose because of the unique management issues and associated comorbidities. This work highlights clues to the identification of this rare monogenic form of adult- onset diabetes.
Donovan
Lois E
LE
University of Calgary Department of Medicine, Division of Endocrinology and Metabolism, Calgary, Alberta, Canada T2R 0X7. loisdon@telus.net
Severin
Naomi E
NE
D000328:Adult; D003067:Coenzymes; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics*; D005080:Exercise Test; D005260:Female; D050172:Genes, X-Linked; D006319:Hearing Loss, Sensorineural / Q000150:complications* / Q000235:genetics; D006801:Humans; D028361:Mitochondrial Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics; D008954:Models, Biological; D009656:North America; D010375:Pedigree; D012356:RNA, Transfer, Leu / Q000235:genetics; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000627:therapeutic use
D003067:Coenzymes; D012356:RNA, Transfer, Leu; D014451:Ubiquinone; C024989:coenzyme Q10