Decreased myocardial taurine levels and hypertaurinuria in a kindred with mitral-valve prolapse and congestive cardiomyopathy.

In a 46-member kindred with consanguineous ancestry, eight progeny in two generations had congestive cardiomyopathy and markedly elevated urinary taurine levels (range, 411 to 536 mg per gram of creatinine [normal +/- S.D., 89 +/- 32]). Ten other family members had late or holosystolic mitral-valve prolapse, and elevated urinary taurine values (range, 215 to 265 mg). In two with mitral-valve prolapse, congestive cardiomyopathy eventually developed while the amounts of urinary taurine doubled. One member with mitral-valve prolapse died suddenly; histologic examination revealed myocardial fibrosis in the papillary muscles and myocardial taurine values of 16.9 +/- 3.0 mumol per gram of protein (normal +/- S.E., 33.2 +/- 3.6). Four other family members with congestive cardiomyopathy had myocardial fibrosis at autopsy or biopsy and mean myocardial taurine levels of 9.2 +/- 2.2 mumol. We conclude that hypertaurinuria and depressed levels of taurine in the myocardium may be associated with one type of mitral-valve-prolapse syndrome and a rapidly progressive form of congestive cardiomyopathy.