Treatment and prevention of genetic diseases

Question 1

A great deal of research has been undertaken into the possibility of effective treatment of genetic diseases. In 1990, the first attempts at human supplementation gene therapy for a single - gene disorder, _____, was performed.

Answer 1

adenosine deaminase deficiency

Question 2

In some conditions, for example, the almost complete prevention or reversal of the phenotypic effects of a genotype is achievable. This includes:

Answer 2

regular venesection for haemochromatosis;

dietary treatment of phenylketonuria (PKU) and medium-chain acyl – CoA dehydrogenase (MCAD) deficiency and with

modern enzyme replacement therapy for Gaucher’s disease & Fabry’s disease.

Question 3

Screening can permit the early removal of pre - cancerous neoplastic lesions in hereditary cancer syndromes such as:

Answer 3

familial adenomatous polyposis (FAP);

MYH polyposis

hereditary non - polyposis colorectal cancer (HNPCC)

Familial breast cancer.

Question 3

Screening can permit the early removal of ____ in hereditary cancer syndromes such as familial adenomatous polyposis (FAP), MYH polyposis, hereditary non - polyposis colorectal cancer (HNPCC) and familial breast cancer.

Answer 3

pre - cancerous neoplastic lesions

Question 4

Patients are increasingly enrolled by clinical geneticists in large multicentre trials of new clinical screening & therapeutic methods. Such trials currently include:

Answer 4

biochemical & ultrasound ovarian screening - ovarian cancer;

Mirena intra - uterine device - mismatch repair gene mutations - endometrial cancer

Question 5

The majority of couples are not aware that they are at risk of having off spring w/ a genetic condition until they have an affected child. This has led to an increased emphasis on prenatal
screening, for example by ____ and by measurement of ____ and other analytes.

Answer 5

fetal ultrasound examination;

maternal serum α - fetoprotein

Question 6

The efficiency of prenatal screening has increased to a point where approximately _____ of cases of fetal Down syndrome can be detected by ____ weeks ’ gestation for a false positive rate of ____.

Answer 6

85 – 90%; 10 – 13; 3.5%

Question 7

More recently, neonatal screening for ____ has been introduced, & it is likely that in the future there will be continued development of population screening, as well as prenatal, neonatal & preconceptional screening, w/c should lead to a reduced frequency of several genetic diseases.

Answer 7

cystic fibrosis