False about hartnup's disease:
Ans: B (Menial retardation is the common presentation) Ref: Nt ? Ison's Textbook of Pediatrics. 19th EditionExplanation:Hartnup diseaseIt is a rare inborn error of metabolism with autosomal recessive inheritance.Neutral amino acids, including tryptophan, are not transported across the brush border epithelium of the intestine and kidneys,This results in deficiency of synthesis of nicotinamideIt causes a photo-induced pellagra-like syndrome.Increased urinary monoamine monocarboxylic amino acids.Cutaneous signs precede neurologic manifestationsEczematous, occasionally vesiculobullous eruption noted on the face and extremities in a glove-and-stocking photodistribution.Hyperpigmentation and hyperkeratosis may supervene and are intensified by further exposure to sunlight.Episodic flares may be precipitated by febrile illness, sun exposure, emotional stress, and poor nutrition.Emotional instability and episodic cerebellar ataxia.Neurologic symptoms are fully reversible.Administration of nicotinamide and protection from sunlight improves both cutaneous and neurologic manifestations.
Defect in neutral aminoacid transport
Mental retardation is the common presentation
Most children are asymptomatic
Photosenitivity
Inborn Errors of Metabolism