EVIDENCE FOR GENETIC ANTICIPATION IN NODAL OSTEOARTHRITIS

Objective-Evidence was sought for genetic anticipation (disease occurr ing at an earlier age in subsequent generations, with increasing sever ity) in nodal osteoarthritis (NOA). Methods-Age at symptom onset and d isease severity was compared within 30 parent/offspring pairs with NOA . Correlation between the offspring age of disease onset and the paren tal age at conception was also assessed. Results-The age at onset of n odal symptoms was earlier in the offspring (43 years (95% confidence i ntervals (CI) 38 to 47) v 61 (CI 58 to 65); mean difference 18 years ( CI 13 to 22): p < 0.001) as was large joint symptom onset (48 years (C I 41 to 55) v 67 (CI 61 to 73); mean difference 20 years (CI 13 to 27) : p < 0.01). A negative correlation existed between age of offspring s ymptom onset and parental age at conception. Fifteen (50%) offspring h ad similar or more extensive disease than their parents. Conclusions-T hese results suggest genetic anticipation occurs in NOA and if confirm ed a search for trinucleotide repeats is warranted.