Genetics

Marfan’s syndrome is a rare genetic disorder of connective tissue caused by a defect in the protein fibrillin-1. Which one of the following is not associated with the condition?

Jul 25, 2025

Genetics, Question bank
A 6-year-old boy is brought to see you in clinic by his mother. She has noticed that he has developed difficulty running and getting up from sitting on the floor. He has a 12-year-old brother who presented at a similar age and is now wheelchair bound. On examination he has proximal muscle weakness with enlarged calf muscles. He is diagnosed with Duchenne’s muscular dystrophy. Which is the most likely mechanism of inheritance of the genetic abnormality?

Jul 25, 2025

Genetics, Question bank
A 23-year-old woman with cystic fibrosis attends her general practitioner surgery for a routine postnatal appointment after giving birth to her second child (a boy). They already have a daughter who has cystic fibrosis. Her partner, the biological parent of both children, has neither cystic fibrosis nor a family history of cystic fibrosis. What is the chance of the couple’s son having cystic fibrosis?

Jul 25, 2025

Genetics, Question bank
Prenatal diagnosis allows the testing of the fetus for diseases or conditions before it is born. Which of the following is NOT used in prenatal diagnosis?

Jul 25, 2025

Genetics, Question bank
Jane suffers from a genetic disease. Two of her three sons and one out of her three daughters also have the disease. Three of her seven grandsons and two of her three granddaughters have the disease. Which of the following modes of inheritance is the most likely mode of inheritance for the disease in this family?

Jul 25, 2025

Genetics, Question bank
The karyotype is the number of chromosomes in the nucleus of a eukaryotic cell. Which of the following human karyotypes is an example of trisomy?

Jul 25, 2025

Genetics, Question bank
Meiosis and mitosis are two types of cell division. Which of the following statements about meiosis is true?

Jul 25, 2025

Genetics, Question bank
Sex linked inheritance of genetic defects can be described as X-linked recessive or X-linked dominant. Which of the following statements concerning sex linked dominant disorders is true?

Jul 25, 2025

Genetics, Question bank
Which among the following is an example of an oncogene?

Jul 25, 2025

Genetics, Question bank
A couple are referred for genetic counselling. Both parents are carriers of a faulty gene PEX1; possession of two abnormal copies of this gene leads to death in infancy. They have lost two children who both died in the first 2 years of life. They have one healthy daughter, who is 3 years of age. What is the risk that their daughter is a carrier?

Jul 25, 2025

Genetics, Question bank