Genetics 🧬

A newly married couple attend the clinic seeking genetic advice. They would like to have a child and would like to know the possibilities of the child suffering from cystic fibrosis. They do not have any symptoms of cystic fibrosis but have been tested to be carriers of the gene. Both of them have siblings who suffer from having the diagnosis of cystic fibrosis and they worry about their children having the disease. What are the chances of their unborn child being affected with cystic fibrosis?

A 33 year old woman who has bilateral cerebellopontine tumours, bilateral sensorineural hearing loss and café au lait spots is pregnant. What are the chances of her child having the same condition?

A 42 year old primiparous woman has a stillbirth at 32 weeks. The baby is noted to have microcephaly, micrognathia, a prominent acciput and prominent calcaneus. What is the SINGLE most likely genetic disorder?

A 30 year old woman presents in the 17th week of her second pregnancy. She missed her antenatal checks and scans and is concerned as her first child was diagnosed with infantile mitochondrial myopathy having developed hypotonia and respiratory insufficiency. She was counselled about the condition and wishes to have a test done to ascertain whether the foetus is affected by the same condition. Which of the following is the SINGLE most appropriate investigation to confirm the presence of the condition?

A 13 year old girl is short for her age. She has a extra folds of skin on the neck and her mother suspects she has Turner syndrome. What is the SINGLE most likely finding in Turner’s syndrome?

A 59 year old man has shown a change in his mood and personality over a 9 month period. He has subsequently developed difficulty with memory and concentration, and then progressive fidgety movements of his limbs and facial musculature. By the time of medical assessment he has frank choreiform movements and a mini-mental state exam of 21/30. He was adopted and therefore no information on his family history is available. He has 3 adult children (27, 30, 33) of whom the 2 youngest are asymptomatic. However, the oldest son has recently been investigated by the neurology department for slightly erratic behavior and fidgety restless movements of both legs. Based on the likely clinical diagnosis, what is the SINGLE most likely made of inheritance?

A 42 year old woman is 16 weeks pregnant. She was late in booking her antenatal appointments and missed her first trimester scan. She is extremely worried about an abnormal chromosomal anomaly in her unborn baby as her first child was born with Down syndrome. What is the SINGLE most definitive investigation at this stage?

A 25 year old mother with fragile X syndrome is pregnant. She has a recent antenatal scan which confirms the sex of the unborn child to be a male. Her partner is unaffected. What is the percentage of her male child having fragile X syndrome?

A 11 year old has increased laxity of joints and hyperelastic skin. He is noted to have mild spinal curvature and a blue sclera. What is the SINGLE most likely diagnosis?

A 34 year old male visits your practice to inquire about the odds of his unborn child having Duchenne muscular dystrophy. From the diagram below, which option best describes the chance of his unborn offspring (represented by the arrow) having Duchenne muscular dystrophy if the child was a male?

A 30 year old woman who is currently pregnant is worried about her child having haemochromatosis. Her husband and her father have developed haemochromatosis. What is the possibility of their unborn child developing haemochromatosis taking into account gender?

A 42 year old female presents to you with the concern of ovarian cancer. She has two older sisters who have both been diagnosed with ovarian cancer and she is worried that she may have avarian cancer as well. A pelvic ultrasound was carried out as part of investigating her symptoms of menorrhagia a month ago and was unremarkable. What is the SINGLE next best step in management of this patient?

Parents who are known to both be carriers of the faulty haemochromatosis gene seek genetic advice as they are planning for a child. What is the possibility of their future child developing haemochromatosis?

A couple attends the genetic clinic with a genetic disease. Below is their pedigree chart:

What is the chance of their unborn male child (marked with the letter “P”) having the disease?

A 15 year old girl presents to the GP surgery with primary amenorrhoea. She has a short stature, low set of ears and a broad chest with widely spaced nipples. What is the SINGLE most likely diagnosis?

A 59 year old man has just become a grandfather. He suffers from Huntington’s disease. His 33 year old daughter has not been genetically tested before and she does not show any features of Huntington’s disease. What are the chances that his grandson would be unaffected?

A 33 year old mother of a child with cystic fibrosis is concerned of her next baby also having cystic fibrosis. She is with the same partner and they both are completely healthy. What is the SINGLE most likely probability of their future child having cystic fibrosis?

A 33 year old African woman who is 12 weeks pregnant discovers that she has sickle cell trait from antenatal screening. Her partner is also tested and is positive for sickle cell trait. What is the likelihood of her child having sickle cell disease?

A 58 year old man is diagnosed with Alzheimer’s disease. He would like to know if he could pass this condition to his children and would like to know more about the genetics of Alzheimer’s disease. Which gene is associated with Alzheimer’s disease?

A 32 year old female has café au lait spots seen at birth. Axillary freckles started to appear in her childhood. Towards her late teens, she began to develop tumours under her skin. Her partner does not have an of these features. What is the probability of her child having the same condition as she has?

A patient comes to seek advice. His wife has just received her routine antenatal screening results, and was found to be a beta-thalassaemia trait. He was investigated a few years ago for an isolated low MCV and was told no further action would be required. Assuming he too has a beta-thalassaemia trait, what is the probability that their baby will be affected by beta-thalassaemia?

A 25 year old man attends his GP surgery with his 2 year old son with concerns about Huntington’s disease. His father was recently diagnosed with Huntington’s disease. His mother is healthy and without medical problems. What are the chances of this 25 year old man having Huntington’s disease in future?

A 48 year old man with Alport syndrome has a male child called Jack with his healthy wife. What is the percentage of Jack having Alport syndrome?

A 7 year old boy has been diagnosed with Becker muscular dystrophy. His 2 alder sisters are well and do not show signs of muscular dystrophy. His mother is now pregnant with her fourth child. The unborn child’s sex has been revealed as female. She wishes to know the chances of her fourth child being a carrier. What is the likelihood of her fourth child being a carrier of the gene mutation for Becker muscular dystrophy?

A young father has been told that he has a diagnosis of Becker’s muscular dystrophy. He and his healthy partner have 2 sons and 2 daughters. Which of the following statements is correct?

A 29 year old woman would like some advice about a concern related to her pregnancy. As the second born in her family, she developed haemolytic disease of the newborn and hopes to understand how likely it is to pass the condition on to her child. She is a primigravida in the 18th week of gestation. Her blood group is O positive, and her husband’s blood group is O negative. Which of the following values describes the likelihood of her newborn developing the same condition?

A 37 year old woman with cardiomegaly has a family history of the disease. Below is the pedigree chart drawn.

What is the mode of inheritance?

A 33 year old woman has been recently diagnosed with invasive breast cancer. Her sister has breast cancer and ovarian cancer. Her mother died from breast cancer. Her daughter has been told by the genetic clinic that there is a possibility that she may develop breast cancer. What is the likely mode of inheritance?

A 22 year old woman has deranged liver enzymes and an asymmetrical tremor. She has a greenish-gold ring on both her comeas that is visible on an ophthalmoscope. His father had a similar history in which his symptoms progressed, and he subsequently died of liver cirrhosis. Which of the following is likely deposited in the cornea?

A neonate’s X-ray shows the following:

He has low set ears and a flat occiput. What is the SINGLE most likely diagnosis?

The parents of two children would like to try for another child. Their first child was diagnosed with cystic fibrosis and their second child is healthy. Both the parents are healthy. What is the chances of their next child being a carrier?

A 9 year old boy has recently been diagnosed with type 1 diabetes mellitus and coeliac disease. Which gene is mainly associated with type 1 diabetes mellitus and coeliac disease?

A 7 year old male child presents with difficulty in climbing stairs. His parents also note that he has difficulties when playing with his friends as he cannot keep up with them. They describe a ‘waddling gait for their son when he attempts to run and complains that he uses his hands to push himself up the stairs rather than his feet. On examination, the tone and power in his lower legs are weakened with absent reflexes and his calves are noted to have an increased diameter bilaterally. What is the SINGLE most likely area for his defect?

A 48 year old man has been diagnosed with Huntington’s disease following evaluation of spontaneous movements. He would like to know the chance of his grandson also having the disease. What is the chance of the grandson being affected with Huntington’s disease?

A 33 year old man with his pregnant wife attends the GP surgery seeking advice. He is known to have haemophilia B. They have just discovered that they are having a male child through an antenatal ultrasound. What is the chance of the unborn male child being affected by the condition?

A 49 year old woman’s younger sister is diagnosed with breast cancer. She is concerned because she has been told that her mother has a BRCA1 mutation. She is worried that she might have that gene mutation too. What is the mode of inheritance for BRCA1 gene mutation?

A grandfather attends the GP surgery and would like to understand his likelihood of carrying the cystic fibrosis gene. He is asymptomatic just like his son but his grandson had recently been diagnosed with cystic fibrosis. What are the chances that he (the grandfather) is a carrier of the cystic fibrosis gene?

A 7 year old male child is brought to the paediatricians office by his concerned mother. She states that he is unable to climb stairs and that he is being bullied in school as he cannot run with his classmates on the playground. Upon examination, it is noted that he has diminished deep tendon reflexes and hypertrophy of his calf muscles bilaterally. What is the SINGLE most likely diagnosis?

A 59 year old man has just become a grandfather. He suffers from Huntington’s disease. His 33 year old daughter has not been genetically tested before and she does not show any features of Huntington’s disease. What are the chances that his grandson would be a carrier?

Parents who are known to both be carriers of the faulty haemochromatosis gene seek genetic advice as they have just found out about their first pregnancy. What is the passibility of their future children developing haemochromatosis taking into account gender?

A 4 year old boy presents to paediatric clinic after a finding of elevated creatine kinase. The mother gives a history of the boy walking at 18 months. He is sluggish and waddles when he runs. He has difficulty climbing stairs and rising from a sitting position. Compared to his older sister at the same age, he has difficulty holding onto small objects. What is the SINGLE most likely diagnosis?

A 4 year old male child is brought to the paediatric clinic by his concerned mother. She states that he cannot run as well as his other nursery friends. He finds difficulty in hopping or jumping. His motor milestones were noted to be delayed since age 3. There are noticeable lower limb weaknesses. On examination, there are reduced deep tendon reflexes of the lower limbs. What is the SINGLE most likely diagnosis?

A 14 year old girl has a recent diagnosis of Turner syndrome. Which of the following statements are correct in relation to women with Turner syndrome?

A mother has a child with 17-alpha-hydroxylase deficiency. She is now pregnant for the second time. What are the risks of her unborn child having congenital adrenal hyperplasia?

Amy’s parents attended the genetic clinic with concerns. Their 5 year old symptomatic boy has recently been diagnosed with cystic fibrosis. Amy has no features of cystic fibrosis. Amy’s parents also do not have features of cystic fibrosis. What is the likelihood of Amy being a carrier for cystic fibrosis?

A 44 year old woman presents with memory loss, poor concentration and inability to recognize household objects. She has right-handed involuntary writhing movement which has just recently started. She reports occasional difficulty in walking. There is a strong family history with similar symptoms. What is the SINGLE mast likely diagnosis?

A 44 year old lady presents to her GP with a headache which has worsened over the past few days. She is worried about her headache as she has been given the diagnosis of polycystic kidney disease. She is extremely concerned because her 38 year old brother recently died of an intracranial insult. She knows he was not hypertensive. What was the SINGLE most likely cause of her brother’s death?

A 45 year old man is recently diagnosed with invasive breast cancer. His two sisters have breast cancer and his father has been diagnosed with prostate cancer. What is the SINGLE most likely gene affected?

A 3 year old child has been diagnosed with Duchenne muscular dystrophy. His mother is now pregnant with her second child who is also male. There is no family history of the disease besides the 3 year old child who is affected. She wishes to know the chances of her second child also being affected. What is the likelihood of her second child having Duchenne muscular dystrophy?

A 3 year old boy presents with rectal prolapse. He is noted to be below the Sth percentile for weight and height. His mother is also concerned because he has a foul- smelling bulky stool that “floats.” She also state that the child has developed a repetitive cough over the last few months. What is the SINGLE most appropriate initial investigation?

A 28 year old lady with a family history of cystic fibrosis comes for genetic counselling and wants the earliest possible diagnostic test for cystic fibrosis for the baby she is planning. She is planning to get pregnant in the near future and she is not in favor of termination. What is the SINGLE most appropriate test to recommend?

Parents of a haemophilia A boy has come to the genetic clinic with concerns of their unborn child. They have just discovered that they are having a male child through an antenatal ultrasound. What is the chance of the unborn male child being affected by the condition?

A 5 year old boy has recurrent chest infections and offensive stool. He is brought by his mother to his GP surgery with concerns that he has another chest infection. They seem to happen every year and sometimes twice in a year. On physical examination, he has coarse inspiratory crepitations. It is also noted that he has finger clubbing. He is prescribed antibiotics for his chest infection. What investigation(s) should be requested?

An 8 year old boy is clinically obese. As a baby he was floppy and difficult to feed. He now has learning difficulties and is constantly eating despite measures by his parents to hide food out of his reach. What is the SINGLE most likely diagnosis?

A 26 year old tall and slender man and his wife have been trying to conceive for the past 3 years. He has been investigated for primary infertility and his recent semen analysis is consistent with azoospermia. On examination, he has small, firm testes. What is the SINGLE most appropriate investigation to be performed to diagnose his condition?

A 30 year old man and wife presents to the reproductive endocrine clinic as they have been trying to conceive for the last 3 years. They have intercourse 3 times a week and do not use contraception. The man is tall and has bilateral gynecomastia. Examination of the testes reveals bilateral small, firm testes. Which is the SINGLE best investigation that could lead to a diagnosis?

A 4 year old child has progressive muscle weakness and frequent falls. He has a waddling gait when he attempts to run. He is unable to hop or jump. His motor milestones seemed to be delayed. His creatine kinase is 20 times higher than normal. On examination, he is toe walking. What is the SINGLE mast likely diagnosis?