July 27, 2000
Genetics and Heredity
Question from Tonawanda, New York, USA:
My three-and-one-half year old son was diagnosed with type 1 diabetes one year ago. I have Polycystic Ovarian Syndrome (PCOS), psoriasis, and psoriatic arthritis. When I was seven months pregnant with him, we did the three-hour glucose tolerance test, and I was considered to have “borderline” gestational diabetes (GDM), controlled by diet alone. Would my having PCOS and/or psoriasis make him more prone to carry the genetic make up for type 1? I understand that they believe they have recently found a gene that predisposes women to have PCOS, and I am wondering about the connection.
The short answer to your question is that neither PCOS nor psoriasis is thought to predispose any children to autoimmune diabetes or indeed any other kind of diabetes in that age group. It is interesting though that some people with PCOS have ovarian antibodies, and, whilst the incidence of these antibodies is no greater than in a control population, it still leaves open the possibility that in some instances those antibodies may reflect autoimmune damage. Psoriasis is associated with chromosomal changes on the long arm of chromosome 11 which is also the site of genes involved in autoimmune diabetes. Perhaps, when the human genome data is fully available, there will be more insights into these possible links.