The genetic history of the British Isles is the subject of research within the larger field of human population genetics. It has developed in parallel with DNA testing technologies capable of identifying genetic similarities and differences between populations.he genetic history of the British Isles is the subject of research within the larger field of human population genetics. It has developed in parallel with DNA testing technologies capable of identifying genetic similarities and differences between populations.
Brittle diabetesâalso called labile diabetesâis a rare but serious form of the disease in which there are dramatic and often unpredictable fluctuations in blood sugar levels. Blood sugar naturally rises and falls throughout the day in response to meals, exercise and other factors.
The patient with clinical variant galactosemia also carries deleterious mutations in both copies of their GALT gene, but one or both mutations leave a small amount of residual GALT activity. In the vast majority of cases, the GALT mutations in classic and clinical variant galactosemia are inherited so that both parents of an affected child are carriers. Rare exceptions occur. Patients with classic galactosemia are sometimes described as having the genetic makeup G/G..