The hyperparathyroidism-jaw tumour syndrome in a Portuguese kindred

The hyperparathyroidism-jaw tumour (HPT-JT) syndrome is an autosomal domina nt disease characterized by the occurrence of parathyroid tumours and fibro -osseous tumours of the jaw bones. Some HPT-JT patients may also develop re nal abnormalities, which include Wilms' tumours, hamartomas and polycystic disease. The HPT-JT gene has been mapped to chromosome 1q25-q31, and we rep ort the clinical and genetic findings in a kindred from central Portugal. H PT-JT was observed in six members from three generations; all had primary h yperparathyroidism (five had parathyroid adenomas, one a parathyroid carcin oma). Ossifying jaw fibromas affecting the disease maxilla and/or mandible were observed in 5/6. Renal cysts (<2.5 cm) were observed in four. Genetic studies using 18 polymorphic loci from chromosome 1q25-q31, together with l eukocyte DNA from 11 family members and tumour DNA from three parathyroids (two adenomas and one carcinoma), revealed loss of tumour heterozygosity in the parathyroid carcinoma only, and the retained haplotype was found to co segregate with the disease in the six affected members. A new Portuguese ki ndred with the HPT-JT syndrome that maps to chromosome 1q25-q31 has been id entified, and these findings will help in the further characterization of t his inherited disorder.