Transcript Genetic Screening

GENOME
EXHIBITION
GENETIC DISEASES
Student’s Copy
Mr and Mrs Tan have a 4 year old boy, named Dexter, who is suffering from learning disabilities.
Feeling that something is wrong with Dexter, Mr and Mrs Tan consult a general practitioner, and are in
turn referred to you, a genetic counsellor.
Dexter Tan (Mr)/ 4 Years Old/ Learning Disabilities
Diagnosis
Cause
What is the disease Dexter is suffering
from? (GN-09)
What is the cause of the disease?
Cystic Fibrosis
Point Mutation (GN-15)
Muscular Dystrophy
Genetic Engineering (GN-37)
Down’s Syndrome
Breast Cancer
Chromosomal Number Change (GN-38)
Mrs Tan is carrying a second child and is eager to know if the unborn child may suffer from the same
disease. You need to select an appropriate technique for Mrs Tan to go through to allay her anxiety.
Genetic Screening
(i) Which method is preferred?
Pre-natal Screening/
Karyotype (GN-19)
DNA Profiling
(GN-35)
Microarray (GN-22)
Gene Sequencing
(GN-21)
(ii) Why is this method preferred?
A genetic diagram is often constructed by a genetic counsellor to predict the chances of a newborn
baby having a certain genetic disease
Genetic Diagram
Do you think you could construct a genetic diagram for the
Tans to explain how Dexter has his disorder?
If yes, construct the genetic diagram at the back.
If no, write down your reason below:
YES
NO
The government decided to offer some help with the treatment for Hector.
Treatment
What kinds of treatment are currently available for someone born with genetic diseases?
(GN-24; GN-39; GN-41; GN-25)
Mrs Gee has a boy named Hector. By the time Hector was six years old, something was amiss. Hector
suffered from loss of muscular function in his lower limbs and required braces to move around.
Mrs Gee consulted a general practitioner about Hector, and was in turn referred to you, a genetic
counsellor for advice.
Hector Gee (Mr)/ 6 Years Old/ Loss of
Muscular Function
Diagnosis
What is the disease Hector is suffering
from? (GN-09)
Cause
Cystic Fibrosis
Muscular Dystrophy
Down’s Syndrome
Breast Cancer
What is the cause of the disease?
Mutation (GN-15)
Genetic Engineering (GN-37)
Chromosomal Number Change (GN-38)
Germaine Poh is a 14 year old Secondary student recently diagnosed with breast cancer. She is very
concerned about her condition. Thus, she has come to you, the genetic counsellor, for a consultation to
find out why she is suffering from breast cancer at such a young age.
Germaine Poh (Ms)/ 14 Years Old
Diagnosis
What is the disease Germaine is suffering
from? (GN-09)
Cystic Fibrosis
Down’s Syndrome
Muscular Dystrophy
Breast Cancer
It was determined that the breast cancer that Germaine is suffering is due to a mutation in a specific
gene.
Cause
(i) Which of the following genes could be mutated to cause breast cancer?
BRCA1
BRCA2
APOE e4
CFTR
GALT
(ii) How did Germaine get a mutation in the gene?
Inherited from parents
Exposure to carcinogens
(cancer-causing agents)
Consumption of genetically
modified organisms
Chemotherapy
Chemotherapy can be used to cure certain breast cancer patients. However, a certain type of
genetic screening has to be carried out to find out whether the patient is suitable for the
treatment.
Genetic Screening
(i) Which type of genetic screening is used to find out the suitability of treatment?
Pre-natal Screening/
Karyotyping (GN-19)
DNA Profiling (GN-35)
Microarray (GN-22)
Gene Sequencing (GN-21)
(ii) Why is this method preferred?