Genetics Module

Second Revision quiz - please answer true or false!

 1    Each son of a man with haemophilia has a 1 in 2 risk of inheriting the condition.

2    The risk of having another child with a neural tube defect is 1 in 200.

3    Genetic testing in childhood should be performed only for conditions where genetic information will enable surveillance for complications.

 4    Approximately 1 in 20 of the white population in the West Midlands is a carrier for cystic fibrosis.

5    The majority of people with Down syndrome have trisomy 21.

6    Prenatal diagnosis by DNA analysis can only be performed on tissue in which the gene is being expressed.

7    Not all children with an autosomal dominant condition (such as neurofibromatosis) will have an affected parent.

8    The karyotype XYY is associated with gynaecomastia, tall stature, infertility and eunuchoid habitus.

9    Children who are carriers of balanced reciprocal translocations can usually be diagnosed because of their dysmorphic features.

 10    A woman with an autosomal dominant disease has a 1 in 2 chance that a daughter will inherit the condition.

11    The children of a man with a disease caused by a mutation in mitochondrial disease will not inherit the disorder from him.

12    The mothers of all boys with Duchenne muscular dystrophy are carriers for the condition.

13    The environmental component of the majority of multifactorial conditions has been identified.

14    The healthy brothers and sisters of a child with congenital adrenal hyperplasia have a 2 out of 3 chance of being a carrier.

15    It can be difficult to detect carriers of autosomal recessive metabolic diseases (such as congenital adrenal hyperplasia) by biochemical assay because of the overlap of levels with the normal range.

16    The sister of two boys who have suffered from X-linked adrenoleukodystrophy has a 1 in 2 risk of being a carrier.

17    A particular characteristic of autosomal dominant inheritance is that all affected people in a family will demonstrate exactly the same degree of severity.

18    If the first child of two parents who are carriers has sickle cell disease, the next three children will be unaffected.

19    Different physical characteristics on examination would allow one to predict whether a baby boy had the karyotype 47,XY+21 (trisomy 21) or an unbalanced 14-21 Robertsonian translocation.

20    More than 40% of children who have congenital sensory neural deafness have a genetic cause.