Why is Mom’s T1D Half as Likely as Dad’s to Pass to Child?

TOPLINE:

Young and adult children of mothers with type 1 diabetes (T1D) are almost half as likely be diagnosed with this condition compared with those with affected fathers, even with a similar genetic risk score. 

METHODOLOGY:

• Individuals with a family history of T1D face 8-15 times higher risk for this condition than the general population, with the risk of inheritance from mothers with T1D being about half that of fathers with T1D; however, it is unclear if the effect continues past childhood and what is responsible for the difference in risk.
• Researchers performed a meta-analysis across five cohort studies involving 11,475 individuals diagnosed with T1D aged 0-88 years to evaluate if maternal T1D conferred relative protection only to young children.
• They compared the proportion of individuals with T1D with affected fathers vs mothers and explored if this comparison was altered by the age at diagnosis and the timing of parental diagnosis relative to the birth of the offspring.
• Lastly, the inherited genetic risk for T1D was compared between those with affected mothers vs fathers using a risk score composed of > 60 different gene variants associated with T1D.

TAKEAWAY:

• Individuals with T1D were almost twice as likely to have a father with the condition than a mother (odds ratio, 1.79; P < .0001).
• The protective effect of maternal diabetes was seen regardless of whether the individuals were diagnosed with T1D before or after age 18 years (P < .0001).
• Maternal diabetes was linked to a lower risk for T1D in children only if the mother had T1D during pregnancy.
• The genetic risk score for T1D was not significantly different between those with affected fathers vs mothers (P = .31).

IN PRACTICE:

“Understanding why having a mother compared with a father with type 1 diabetes offers a relative protection against type 1 diabetes could help us develop new ways to prevent type 1 diabetes, such as treatments that mimic some of the protective elements from mothers,” said Lowri Allen, MBChB, an author of this study, in a news release from meeting organizers.

SOURCE:

The study was led by Allen from the Diabetes Research Group, Cardiff University, Cardiff, United Kingdom, and was published July 26, 2024, as an early release from the Annual Meeting of the European Association for the Study of Diabetes 2024, Madrid, September 9-13. 

LIMITATIONS:

This abstract did not discuss any limitations. The number of individuals and parents with T1D in the meta-analysis was not disclosed. The baseline risk for T1D among individuals with a mother, father, or both or no parent with T1D was not disclosed. The number of people with T1D under and over age 18 was not disclosed, nor were the numbers of mothers and fathers with T1D. The relative risk in individuals having no parent with T1D was not disclosed. Moreover, the race and ethnicity of the study populations were not disclosed. 

DISCLOSURES:

The Wellcome Trust supported this study. The authors declared no relevant conflicts of interest. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.