Patent Evaluation: Detection of a mutant collagen gene and its potential as a diagnostic for genetic predisposition for osteoporosis

Abstract

Novelty: Methods are disclosed for the detection of post-menopausal osteoporosis by the use of DNA probes which can identify some of the major mutant collagen genes. This will be of use in the diagnosis of type-1 or post-menopausal osteoporosis which affects women 10-15 years after menopause and is characterised by a resulting in increased frequency of bone fractures.

Biology: The DNA sequence of the 3' half of the human pro-cxl(1) gene is described. From a patient who had been diagnosed as having osteoporosis, PCR was used to amplify and then sequence all of the pro-al(1) gene from total RNA. The results showed a mutation of GGT coding for glycine to AGT which codes for serine, at position 661. This was confirmed by the sequencing of the genomic copy of the same gene. The other family members could then be tested in the same way to detect any mutation at that particular allele. The preferred test kit would be a hybridisation assay designed with DNA probes which could distinguish between the wild type and the mutant genes. Several DNA sequences are shown for the detection of different mutations in this collagen gene.