[Valvular prolapse in autosomal dominant polycystic kidney].

BACKGROUND

The involvement of the cardiovascular system in hereditary connective tissue disorders has been known for a long time and produces abnormalities that usually affect valves and arterial walls. Valvular diseases in typical autosomal dominant illnesses such as polycystic kidney (PK) have recently been reported.

METHODS

To test the prevalence of valvular prolapses in this disease, we studied [with clinical, chest x-ray, electrocardiographic, and echocardiographic (monobidimensional and Doppler) examination] 21 subjects with PK (Group A) and 34 unaffected relatives (Group B). 36 subjects comparable in sex, age, blood pressure, body build and renal function, with other kinds of kidney diseases, were the control group (Group C).

RESULTS

In group A, 7 subjects (33.3%) were found affected by mitral valve prolapse (MVP), of whom 3 also had mitral incompetence, 4 tricuspid valve prolapse and 2 aortic cusp prolapse with mild valvular insufficiency. Another 2 patients had evidence of mitral and aortic incompetence, respectively, without valvular prolapse, annulus ectasia or morphological features of a rheumatic valvular disease. In Group B, 8 subjects (23.5%) had MVP; In Group C, MVP was seen in only 1 patient (2.7%) and aortic incompetence in one other. Statistical analysis confirmed the significance of the greater prevalence of MVP in group A and B in comparison with group C (p < 0.01).

CONCLUSIONS

The high prevalence of valvular abnormalities in autosomal dominant PK suggests a common genetic disorder producing a defect in the extracellular matrix. An alternative hypothesis is that of two discrete yet adjacent genes.