MUTYH-associated polyposis (MAP) is an autosomal recessive cancer predisposition syndrome. Gujarati heritage is enriched in patients with MAP. Endogamy is frequent in this community. Among ethnicity-matched participants of the 100 000 Genomes Project, the frequency of recurrent pathogenic MUTYH variants in most populations is rarer than that at which testing of reproductive partners of carriers is usually considered. However, MUTYH c.1438G>T (p.Glu480Ter) in participants of Gujarati heritage is relatively common (~1 in 75). We recommend targeted testing for partner(s) of a carrier of MUTYH variant(s) if of Gujarati heritage, to inform reproductive decision-making/management of children. Existing UKCGG guidance is unchanged for other populations.
In the UK, testing of reproductive partners (‘partner testing’) of carriers of recessive traits or individuals affected by recessive disorders is rarely indicated, but may be required in certain circumstances, where there is a relatively high likelihood of having a child affected by a recessive condition—that is, where patients…