Kwashiorkor, a form of malnutrition, is caused by deficiency of which of the following ?

Correct — option (2), Protein.

Kwashiorkor is the classic form of protein deficiency malnutrition in young children. It is described as severe protein malnutrition marked by oedema (swelling) and an enlarged liver with fatty deposits.

Its other signs include a distended abdomen, thinning and loss of colour in the hair, and skin changes (dermatitis). The swelling in the feet and legs separates it from marasmus.

The name comes from the Ga language of coastal Ghana and refers to the illness a child gets when a new baby arrives and it is weaned. The Jamaican paediatrician Cicely Williams published a formal description of it in 1933 and introduced the name in 1935.

One caution: researchers hold that low protein alone does not fully explain how kwashiorkor develops, and its exact cause is still debated. Protein deficiency remains the accepted answer to this question.

The idea to remember: kwashiorkor is protein deficiency with oedema; marasmus is overall energy deficiency with severe wasting.

Why the others are wrong

• (1)
  Selenium — Selenium is a trace mineral, not a macronutrient. Its deficiency is linked to Keshan disease, a disease of the heart muscle named after Keshan County in China, where it was first described. It occurs in areas with selenium-poor soils.

  Selenium is built into selenoproteins, including enzymes that protect cells from oxidative damage and enzymes that activate thyroid hormone. Kwashiorkor is not a trace-mineral disorder.

• (3)
  Carbohydrates — Carbohydrates are the body's main source of energy. A prolonged shortage of total dietary energy leads to marasmus: severe wasting of fat and muscle, without the oedema of kwashiorkor.

  Both conditions are forms of protein–energy malnutrition, and a child can show features of both (marasmic kwashiorkor). But the form defined by protein shortage is kwashiorkor, not a carbohydrate deficiency.

• (4)
  Chromium — Chromium is a trace element linked to the action of insulin. Reported deficiency cases have involved patients fed only intravenously for long periods, who developed impaired glucose tolerance that improved when chromium was added.

  That is a disorder of sugar handling. Kwashiorkor is a protein–energy malnutrition, unrelated to chromium.

Protein–energy malnutrition covers diets short in protein, energy (calories), or both. Its two classic severe forms in children are kwashiorkor and marasmus.

Proteins are made of amino acids, some of which the body cannot make and must get from food. They build and repair tissue, and blood proteins such as albumin help hold fluid inside blood vessels.

Kwashiorkor's oedema is often explained by low blood albumin letting fluid leak into tissues, though research treats this as only part of the picture.

Marasmus results from a severe overall shortage of energy. The body uses up its own fat and muscle, producing extreme thinness without oedema.

Key facts

• Kwashiorkor is severe protein malnutrition in children, marked by oedema and an enlarged liver with fatty deposits.
• Marasmus is mainly an energy (calorie) deficiency, marked by severe wasting and weight loss rather than oedema.
• The word kwashiorkor comes from the Ga language of coastal Ghana; Cicely Williams introduced the name in 1935.
• Selenium deficiency is linked to Keshan disease, a heart-muscle disease named after Keshan County in China.
• Research holds that low protein intake alone does not fully explain how kwashiorkor develops; its exact cause is still debated.

Common traps

• Carbohydrate (energy) shortage points to marasmus, not kwashiorkor. Both are protein–energy malnutrition, so check which nutrient the stem names before matching the disease.
• Selenium and chromium are trace minerals. Kwashiorkor is a macronutrient disorder, so a trace element in the options belongs to a different family of deficiencies.
• Oedema can make a child with kwashiorkor look puffy rather than thin, hiding the malnutrition. Swelling, not visible thinness, is its distinguishing sign.

UnlockIAS will link similar questions from RAS Pre 2016 and 2013 here once those papers are published on this site.

• practice — not a real PYQ

  Marasmus, a form of malnutrition in children, results mainly from a prolonged deficiency of

  • (a)Iodine
  • (b)Overall dietary energy (calories)
  • (c)Vitamin C
  • (d)Selenium
  Answer(2) — Marasmus is a severe shortage of total energy, which makes the body use up its own fat and muscle. Option (1), iodine, is linked to goitre; option (3), vitamin C, to scurvy; option (4), selenium, to Keshan disease.
• practice — not a real PYQ

  Which one of the following signs distinguishes kwashiorkor from marasmus?

  • (a)Retarded growth
  • (b)Oedema of the feet and legs
  • (c)Low body weight for age
  • (d)Weakness and fatigue
  Answer(2) — Oedema is the hallmark of kwashiorkor and is absent in marasmus. Options (1), (3) and (4) are seen in both forms of protein–energy malnutrition, so none of them tells the two apart.