Familial calcium pyrophosphate dihydrate deposition disease. A Tunisian kindred.

INTRODUCTION

Familial calcium pyrophosphate dihydrate deposition disease (CPDD) is uncommon, with about 50 affected families identified to date in the world. Genetic studies in familial CPDD are focusing on the ANKH gene. We report a new Tunisian kindred with CPDD.

PATIENTS AND

METHODS

The development of CPDD in a patient who was only 35 years of age prompted a family study. A medical history, physical examination, and radiographs were performed in 103 family members older than 18 years.

RESULTS

Fifteen family members had CPDD. There were 10 men and five women, with a mean age of 59.4 years. Onset was usually in the third or fourth decade. Four clinical patterns were found: Five patients had pseudogout, five had pseudoosteoarthritis, three had asymptomatic disease, and two had pseudorheumatoid arthritis. Inheritance was autosomal dominant with low penetrance. No associations with specific HLA antigens were found. The disease was mild. These characteristics fit the description of Gaucher type 1 familial CPDD.

CONCLUSION

Inherited autosomal dominant CPDD with low penetrance was found in 15 members of a Tunisian kindred. The disease was mild. We are planning a genetic study including tests for ANKH gene mutations in this kindred.