Nutrition/Metabolic

Question 1

What are symptoms of riboflavin deficiency?

Answer 1

It occurs because of poor intake, reduced absorption in patients with biliary atresia or hepatitis, or poor absorption in those receiving probenecid, phenothiazine, or oral contraceptives. Signs and symptoms of riboflavin deficiency include cheilosis, glossitis, a variety of ocular problems (keratitis, conjunctivitis, and corneal vascularization), and seborrheic dermatitis.

Question 2

What are symptoms of vitamin B6 (pyridoxine) deficiency?

Answer 2

Occurs in patients with low levels of this vitamin in their diet, because of a vitamin B6–dependent syndrome whereby enzyme structure problems result in poor absorption, or a result vitamin inhibition due to drug ingestion including isoniazid, penicillamine, corticosteroids, and anticonvulsants. Seizures, peripheral neuritis, dermatitis, and microcytic anemia are commonly seen evidence of deficiency.

Question 3

What are signs of folate deficiency in children?

Answer 3

Megaloblastic anemia, glossitis, pharyngeal ulcers, and impaired immunity.

Question 4

What are symptoms of niacin deficiency (pellagra)?

Answer 4

Symptoms include inflamed skin, diarrhea, dementia, and sores in the mouth

Question 5

What are symptoms of biotin deficiency?

Answer 5

Classically caused by eating high quantities of egg whites (contains avidin which binds tightly to biotin). Symptoms include: Rashes (including red, patchy ones near the mouth), fine and brittle hair, alopecia, anemia, seborrheic dermatitis, fungal infections, lethargy, paresthesias, and anorexia.

Question 6

What vitamin should patient with sickle cell disease be supplemented with?

Answer 6

Folate - because of ongoing compensatory erythropoiesis.

Question 7

What are contraindications to breast feeding?

Answer 7

Infections such as active TB, HIV, HSV infection of the breast, malaria, septicemia, and typhoid fever. Medications that are clearly contraindicated include lithium, cyclosporin, antineoplastic agents, illicit drugs including cocaine and heroin, amphetamines, ergotamines, bromocriptine (which suppresses lactation), and tetracycline. Note that anticonvulsants (especially carbamazepine, phenytoin, and valproic acid) are generally considered safe. Galactosemia of the infant is also contraindicated (should receive soy-based formula).

Question 8

What nutrients is goat’s milk deficient in for an infant?

Answer 8

Folate and iron

Question 9

What are features of biotinidase deficiency (enzyme responsible for breakdown of biocytin to free biotin)?

Answer 9

Deficiency of the enzyme, which is inherited as an autosomal recessive trait, results in malfunctioning of the biotin-dependent mitochondrial enzymes and in organic acidemia. Clinical problems related to the deficiency appear several months or years after birth and include dermatitis, alopecia, ataxia, hypotonia, seizures, developmental delay, deafness, immunodeficiency, and metabolic acidosis. The treatment is lifelong administration of free biotin.

Question 10

What is maple syrup urine disease?

Answer 10

Maple syrup urine disease presents early in life, frequently before the state screen results are back. Symptoms begin several days after birth and rapidly progress to convulsions and death in 2 to 4 weeks if not treated. The distinctive odor of caramel or maple syrup starts after 1 to 2 days of life, but is variable in intensity. The diet consists of careful regulation of the intake of leucine, isoleucine, and valine.

Question 11

What vitamin should patients with homocystinuria be supplemented with?

Answer 11

B6 (folic acid and B12 may also be beneficial)

Question 12

What condition leads to elevated blood or urine succinylacetone?

Answer 12

Tyrosinemia

Question 13

What are the symptoms of tyrosinemia?

Answer 13

Liver and renal tubular dysfunction, growth failure, rickets, and a variety of neurologic symptoms such as peripheral neuropathy

Question 14

What is Morquio syndrome?

Answer 14

A rare AR metabolic disorder that leads to the accumulation of mucopolysaccharides. Symptoms include short stature, moderate kyphosis or scoliosis, mild pectus carinatum (“pigeon chest”), atlanto-axial instability, joint laxity, dysplastic hips, large unstable knees, large elbows and wrists, flat feet, a duck-waddling gait, mid-face hypoplasia and mandibular protrusion, thin tooth enamel, corneal clouding, and mild hepatosplenomegaly

Question 15

What disorder causes an infant’s wet diapers to turn black when exposed to the air?

Answer 15

Alkaptonuria - AR disorder caused by a deficiency of homogentisic acid oxidase. Patients are asymptomatic in childhood but may develop arthritis later in life

Question 16

What is von Gierke disease?

Answer 16

Results from deficiency of the enzyme glucose-6-phosphatase. The deficiency impairs the ability of the liver to produce free glucose from glycogen and from gluconeogenesis. Patients have massive hepatomegaly, doll-like facies, thin extremities, and are short for their age. They have hypoglycemia, hyperlipidemia, and lactic acidosis. Serum electrolytes may be low (e.g. low Na+ and K+)

Question 17

Why do children with undiagnosed cystic fibrosis often develop easy nose bleeds and bruising?

Answer 17

Vitamin K deficiency from decreased absorption of fat-soluble vitamins

Question 18

How does glucose-6-phosphatase deficiency (von Gierke disease) present (results in impaired conversion of glycogen to glucose)?

Answer 18

Presents in infancy with a doll-like face, thin extremities, short stature, and hepatomegaly. Patients have hypoglycemia (often resulting in seizures) and lactic acidosis (due to build up in the liver). Other lab findings include hyperuricemia, hyperlipidemia, and ketonuria