Question

Mention the symptoms of Phenylketonuria and Down’s Syndrome.

Hint:

Remember: PKU → Metabolic defect; Down’s → Chromosome 21 trisomy.

Answer 1

Concept: Phenylketonuria (PKU) and Down’s Syndrome are genetic disorders that affect physical and mental development.
Step 1: Symptoms of Phenylketonuria (PKU).

• Mental retardation due to accumulation of phenylalanine
• Developmental delays in infants
• Seizures (convulsions)
• Musty or mousy odor of urine and sweat
• Hypopigmentation (light skin and hair)
• Behavioral problems such as hyperactivity

Step 2: Cause of PKU.

• Caused by deficiency of enzyme phenylalanine hydroxylase
• Leads to accumulation of phenylalanine in blood

Step 3: Symptoms of Down’s Syndrome.

• Mental retardation and delayed development
• Flat facial profile and slanting eyes
• Short stature and broad hands with a single palmar crease
• Protruding tongue and small ears
• Congenital heart defects (in some cases)
• Weak muscle tone (hypotonia)

Step 4: Cause of Down’s Syndrome.

• Caused by trisomy of chromosome 21 (presence of an extra chromosome)

Step 5: Conclusion.
Thus, PKU is a metabolic disorder while Down’s Syndrome is a chromosomal disorder, both showing distinct symptoms.