Frequency of HLA antigens in Graves' hyperthyroidism and mitral valve prolapse.

BACKGROUND AND AIMS OF THE STUDY: An association between Graves' hyperthyroidism (G) and mitral valve prolapse (MVP) has been reported, but possible genetic linkage between the two disorders has not.

METHODS

One hundred and five patients (pts) with G were studied after therapy, in a euthyroid state. MVP (auscultatory plus echocardiographic findings) was present in 33 pts (31%). Frequency of human lymphocyte antigens (HLA) in pts with G and in pts with G plus MVP was compared to 170 normal subjects (NL). There was no difference in HLA-A antigens among the three groups.

RESULTS

The frequency of HLA B-15 was greater in pts with G plus MVP (18.9%) compared to NL (3%) and to G without MVP (4.2), p < 0.01. The frequency of HLA-B39 was greater in G without MVP (13.8%) compared to NL (4.1%), p < 0.01. The HLA DRB1*1601-2 was more frequent in G with (30.3%) or without (29.2%) MVP compared to NL (13.5%), p < 0.01. The frequency of HLA DRB1*1401-10 and DQA1*0104 were greater in NL (16.5%) compared to G with (3.0%) or without (4.2%) MVP, p < 0.01.

CONCLUSIONS

The data confirmed previous observations that the frequency of MVP is high in pts with G. Further, the data indicated a possible genetic linkage between the two abnormalities.