Original ArticleTelomere length analysis in Down syndrome birth

- In this study we include 170 mothers of Down syndrome child and 186 age matched mothers of euploid child with their newly born babies as participants.
- We categorised the mothers of Down syndrome child according to age (old >35 years, young <35 years) and stage of meiotic nondisjunction NDJ (NDJ in meiosis I = MI, and II = MII respectively). Telomere length (TL) was measured for each participants.
- The result reveals that MII old mothers do have shortest TL (p < 0.001).
- The study shows that the babies from older mother have longer TL (p < 0.001).
- Down syndrome babies have longer TL than euploid individual (p < 0.001).

Human reproductive fitness depends upon telomere chemistry. Maternal age, meiotic nondisjunction error and telomere length of mother of trisomic child are someway associated. Reports exhibiting maternal inheritance of telomere length in Down syndrome child are very scanty. To investigate this, we collected peripheral blood from 170 mothers of Down syndrome child and 186 age matched mothers of euploid child with their newly born babies. Telomere length was measured by restriction digestion - southern blotting technique. Meiotic nondisjunction error was detected by STR genotyping. Subjects are classified by age (old >35 years and young ˂35 years) and by meiotic error (MI and MII). Linear regression was run to explore the age - telomere length relationship in each maternal groups. The study reveals that with age, telomere erodes in length. Old MII mothers carry the shortest (p ˂ 0.001), control mothers have the longest telomere and MI lies in between. Babies from older mother have longer telomere (p ˂ 0.001) moreover; telomeres are longer in Down syndrome babies than control babies (p ˂ 0.001). To conclude, this study represents not only the relation between maternal aging and telomere length but also explore the maternal heritability of telomere length in families with Down syndrome child.