HartNup's Disease (Neutral
aa, Niacin deficiency,
Nicotinamide)
- autosomal recessive
- disorder of neutral amino acid
- most are asymptomatic
- can present with a sunburn-like
rash plus ataxia and
behavioral disorders.
- Symptoms are due to Niacin deficiency, which is due to
impaired tryptophan
transport
- Treat with nicotinamide.
Other amino acid disorders include:
Cystinosis, Cystinuria
CHLA Board Review 2005