Medscape: Development mutations may be present in only one of monozygotic twins

Identical twins are thought to possess the same set of genes, but a new research study has found that mutations may be present at birth in one twin, but not the other. The findings have important research implications because differences between identical twins were assumed by researchers to be the result of environmental and not genetic factors.

Reuters Health reporter Marilynn Larkin spoke via email with Anil Menon, PhD, professor of molecular genetics, biochemistry and microbiology at the UC College of Medicine, and other researchers about the new study’s findings. Menon called the study ‘unique and groundbreaking.’

"The gold standard for making estimates of environmental versus genetic contributions to variance in a trait has been the comparison of data from cohorts of monozygotic twins ('identical') with cohorts of dizygotic twins ('non-identical'). Statistical analysis is then used to estimate the genetic contribution to variance in the trait (heritability)," he told Reuters Health by email.

"The novelty of this study is the demonstration that monozygotic twins themselves have a certain intrinsic variability in their genomes, and therefore previous studies using comparison of monozygotic and dizygotic twins might actually be underestimating the contribution of genetics in variation of the trait being studied," Menon told Reuters Health.

Read the entire story in Medscape online.

Learn more about Anil Menon, PhD online.

Featured image at top: Anil Menon, PhD, in the UC College of Medicine. Photo/Colleen Kelley/UC Creative + Brand