Th2L03 Genetic testing

Question	Answer
What is amniocentesis	A technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from a needle inserted into the uterus, is analysed to detect certain genetic and congenital defects in the foetus
When is amniocentesis usually carried out	during weeks 15-20 of pregnancy
What are the risks of amniocentesis	It is invasive and carries 1% chance of miscarriage
What safe-guards are their for amniocentesis	only offered if combined test shows risk (1Ks carried out every year)
What is a combined test	blood test that indicates if there is a significant risk the baby will develop a serious condition or abnormality
What is the combined test carried out	in Europe at 9-14 weeks, US at 11-13 weeks of pregnancy
What is involved in amniocentesis analysis	(1) Foetal cells isolated (2) Quantification of chromosomes (Q-PCR 1 day, 2 hours to test) (3) Karyotype (2 weeks), grown in culture medium
What is the Q-PCR	measures the quantity of a target sequence; used to study gene expression
What is the significance of maternal age	increases the risk of trisomy Esp. after age 33

Resource summary

	Created by Emma Allde over 7 years ago