Genetics Flashcards
What reasons may there be to refer someone to genetics in obstetrics?
Family history of genetic conditions
Diagnosed with genetic conditions
Genetic counselling
What do people need to know before undergoing a genetic test?
What the test is for
How likely the test is to be positive
The outcome if the test is positive or negative
Risk of false positive/negative
Implications for other family members of positive result
DNA will be stored
What are the 2 types of pregnancy screening?
Targetted
Whole population
What is noninvasive prenatal testing?
Fetal cell-free DNA can be found in the mother’s blood stream from around the 10th week of pregnancy which can be collected by taking maternal blood and can be tested for chromosomal abnormalities
What are common RECESSIVE disorders that raise screening issues?
CF in Europe Sickle cell anaemia in Africans Thalassaemias in Mediterraneans and Asians Ashkenazi jewish people at high risk Tay-Sachs disease BRCA 1
What is cystic fibrosis?
Defect of cellular chloride transport leading to reduced ability to push water out of the cell, leading to thickened mucous secretions
What screening is done in newborns?
Clinical examination
Hearing test
Heel prick test
Why are babies screened?
Enable early detection of pre-symptomatic babies
Enable early treatment to improve health
Reduce anxiety caused by uncertainty over symptoms
What do we screen newborns for?
Phenylketonuria Congenital hypothyroidism Sickle cell disorders CF Medium chain acyl-CoA dehydrogenase deficiency Homocysteinuria Isovaleric acidaemia Maple syrup urine disease Glutaric aciduria type 1
What is PKU?
Person with the condition can’t break down phenylalanine which leads to severe irreversible mental disability if not treated
What is treatment of PKU?
Strictly controlled diet
When should treatment for PKU start?
By 21 days of age
What is medium chain Acyl-CoA dehydrogenase deficiency?
Babies with this condition can’t easily break down fat to make energy which can lead to serious life-threatening symptoms if babies aren’t feeding well
