1. A 7-year-old boy presents with recurrent bacterial and fungal infections. He has a history of abscess formation in multiple organs. His mother is asymptomatic, but her brother had similar infections and died as a child. Genetic analysis reveals a mutation in the gene encoding NADPH oxidase. What is the most likely mode of inheritance? […]
Single Gene Inheritance- Multiple-Choice Questions Read More »
Question 1: What is the definition of a single-gene disorder? Answer: Single-gene disorders are genetic conditions caused by mutations in a single gene. They can follow autosomal dominant, autosomal recessive, or X-linked inheritance patterns. Question 2: Name two examples of autosomal dominant single-gene disorders. Answer: Examples include Huntington’s disease and Marfan syndrome. Question 3: What
Table 1: Autosomal Recessive (AR) Disorders Mnemonic: “Can People Stop Talking While Cooking Toast And Fries?” Letter Disorder Clinical features C Cystic Fibrosis (CF) Thick mucus, lung infections, salty sweat. P Phenylketonuria (PKU) Intellectual disability, musty odor. S Sickle Cell Anemia Pain crises, anemia, malaria resistance. T Tay-Sachs Disease Neurodegeneration, cherry-red macula. W Wilson’s Disease
Table 1- Basic Genetic Concepts Term Definition Example/Notes Gene A segment of DNA that encodes for a protein or RNA. BRCA1 gene for DNA repair. Allele A variant form of a gene. Dominant (A) or recessive (a). Locus The specific physical location of a gene or DNA sequence on a chromosome. The CFTR gene is
Key Terminologies and Concepts in Genetics For Easy Reference Read More »
Question 1: A 3-month-old male infant presents with delayed motor development and orange, sand-like crystals in his diaper. His parents report he constantly chews on his fingers and lips, causing bleeding. Based on these symptoms, what is the most likely diagnosis? A. Adenosine deaminase deficiency B. Gouty arthritis C. Lesch-Nyhan Syndrome D. Orotic aciduria E.
Nucleotide metabolism-Multiple-choice questions with explanations Read More »
Question 1: What is the initial step in the synthesis of both purine and pyrimidine nucleotides? Answer: The initial step in the synthesis of both purine and pyrimidine nucleotides is the synthesis of PRPP (5-phosphoribosyl-1-pyrophosphate) from D-ribose-5’-P. Question 2: What is the significance of Mycophenolic acid in purine nucleotide biosynthesis? Answer: Mycophenolic acid is an
Nucleotide metabolism- Short-answer questions Read More »
1. An exclusively breast-fed infant presents with vomiting, weight loss, jaundice, hepatomegaly, and bilateral cataracts. Which condition is most likely responsible for these symptoms? A. Breast milk jaundice B. Classical Galactosemia C. Hereditary fructose intolerance D. Type 1 Diabetes mellitus E. Von Gierke’s disease Correct Answer: B. Classical Galactosemia Explanation: Classical galactosemia is a rare
Fructose and Galactose metabolism- Multiple-choice questions with explanations Read More »
Question 1: What are the two ways fructose exists in food? Answer: Fructose exists in food as a monosaccharide (free fructose) or as a unit of a disaccharide (sucrose). Question 2: What is the name of the transporter protein responsible for fructose absorption in the intestine? Answer: Fructose absorption in the intestine occurs via facilitated
Fructose and Galactose metabolism- Short-answer questions Read More »
Disorder Defective Enzyme/Transporter Clinical Picture Mnemonic Phenylketonuria (PKU) Phenylalanine hydroxylase Musty body odor, intellectual disability, seizures, pale skin, eczema Pale kids with Krappy Urine Alkaptonuria Homogentisic acid oxidase Black urine, ochronosis (bluish-black pigmentation in connective tissues), arthritis Black CAP: Cartilage, Arthritis, Pigmentation Maple Syrup Urine Disease (MSUD) Branched-chain α-ketoacid dehydrogenase Sweet-smelling urine, poor feeding,
Summary of Amino acid disorders with easy recall mnemonics Read More »
Question 1: What is the primary function of the urea cycle in humans? Answer: The urea cycle converts ammonia, a highly toxic byproduct of amino acid metabolism, into urea, a less toxic compound that can be safely excreted in urine. This process is vital for maintaining nitrogen balance in the body. Question 2: Which cellular
Ammonia Disposal – Short-answer questions Read More »
