Genetic Disorders (Diseases and Treatment)

Total Questions: 23

1. Which one of the following is not an genetic disease? [U.P.P.C.S. (Pre) 2017]

Correct Answer: (a) Night blindness
Solution:Night blindness is not a genetic disease. The cause of Night blindness is deficiency of vitamin A. Albinism is genetic disease in which the pigments called melanin is partially or completely absent in the skin, hair and eyes. Haemophilia is a genetic sex-linked disease. Colour blindness is also a genetic disease.

2. Phenylketonuria is an example of an inborn error of metabolism. This 'error' refers to : [I.A.S. (Pre) 1994]

Correct Answer: (c) Inherited lack of an enzyme
Solution:Phenylketonuria (PKU) is a disease caused by a metabolic disorder inherited as a recessive trait. The dominant gene 'P', in this case, codes for the enzyme, phenylalanine hydroxylase, formed in the liver cells. This enzyme catalyzes conversion of phenylalanine to tyrosine.

In homozygous recessive genotypes, the absence of this enzyme causes a high level of phenylalanine in blood and tissues fluids. The phenotypic effects include a progressive mental retardation starting a few month after birth, seizures, and anomalies of teeth enamel and bones.

3. A person affected by phenylketonuria disease suffers form: [R.A.S/R.T.S.(Pre) 1999]

Correct Answer: (c) Mental idiocy
Solution:Phenylketonuria (PKU) is a disease caused by a metabolic disorder inherited as a recessive trait. The dominant gene 'P', in this case, codes for the enzyme, phenylalanine hydroxylase, formed in the liver cells. This enzyme catalyzes conversion of phenylalanine to tyrosine.

In homozygous recessive genotypes, the absence of this enzyme causes a high level of phenylalanine in blood and tissues fluids. The phenotypic effects include a progressive mental retardation starting a few month after birth, seizures, and anomalies of teeth enamel and bones.

4. The famous 'Bubble Baby Disease' is so called because: [U.P.P.C.S. (Pre) 1997]

Correct Answer: (c) The suffering baby is treated in a germ-free plastic bubble
Solution:Bubble Baby Disease (severe combined immunodeficiency: SCID) is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations. There are several forms of SCID. The famous 'Bubble Baby Disease' is named so as the suffering baby is treated in a germ-free plastic bubble.

5. Haemophilia is a genetic disease carried by - [I.A.S. (Pre) 1993]

Correct Answer: (b) Women, appear in men
Solution:Haemophilia is a genetic sex-linked disease in which blood clotting takes a long time in a patient (up to 24 hours) due to lack of thromboplastin protein in blood plasma.

Womencarry it while it appears in men (because men have one X chromosome but women have two). It is also called bleeder's disease which was first found in Queen Victoria. So it is also known as royal haemophilia.

6. Haemophilia is: [U.P. Lower Sub. (Pre) 2015]

Correct Answer: (d) A hereditary defect
Solution:Haemophilia is a genetic sex-linked disease in which blood clotting takes a long time in a patient (up to 24 hours) due to lack of thromboplastin protein in blood plasma.

Womencarry it while it appears in men (because men have one X chromosome but women have two). It is also called bleeder's disease which was first found in Queen Victoria. So it is also known as royal haemophilia.

7. Which one of the following genetic diseases is sex-linked? [U.P.P.C.S. (Spl.) (Pre) 2008, I.A.S. (Pre) 1999]

Correct Answer: (a) Royal haemophilia
Solution:Haemophilia is a genetic sex-linked disease in which blood clotting takes a long time in a patient (up to 24 hours) due to lack of thromboplastin protein in blood plasma.

Womencarry it while it appears in men (because men have one X chromosome but women have two). It is also called bleeder's disease which was first found in Queen Victoria. So it is also known as royal haemophilia.

8. Haemophilia is a hereditary disease which affects as - [U.P.P.C.S. (Pre) 2003]

Correct Answer: (d) Absence of blood clotting
Solution:Haemophilia is a genetic sex-linked disease in which blood clotting takes a long time in a patient (up to 24 hours) due to lack of thromboplastin protein in blood plasma.

Womencarry it while it appears in men (because men have one X chromosome but women have two). It is also called bleeder's disease which was first found in Queen Victoria. So it is also known as royal haemophilia.

9. The heritable disease is: [U.P.P.C.S. (Mains) 2007, Uttarakhand P.C.S. (Pre) 2006]

Correct Answer: (a) Haemophilia
Solution:Haemophilia is a genetic sex-linked disease in which blood clotting takes a long time in a patient (up to 24 hours) due to lack of thromboplastin protein in blood plasma.

Womencarry it while it appears in men (because men have one X chromosome but women have two). It is also called bleeder's disease which was first found in Queen Victoria. So it is also known as royal haemophilia.

10. Which of the following is not a genetic disorder? [Uttarakhand P.C.S. (Pre) 2010]

Correct Answer: (c) Irritable Bowel Syndrome (IBS)
Solution:Down syndrome, haemophilia and sickle cell anaemia are hereditary diseases. Irritable Bowel Syndrome (IBS) is not a genetic disorder, it is a common gut disorder.

The cause is not well known. Symptoms can be quite variable and include tummy (abdominal) pain, bloating and sometimes bouts of diarrhoea and/or constipation.