A 2 year old male child presented with pellagra like lesions with passage of amino acids in urine.Two siblings also
having the same complaints.The parents are normal.What is your diagnosis?
A. Phenyl Ketonuria
D. Hartnup’s Disease
Autosomal Recessive Condition.
Named after first family in which the disorder identified.
Defective absorption of Tryptophan and other Neutral Amino Acid from Intestine and Renal Tubules
The transporter protein for these amino acids (B0AT1) is encoded by the SLC6A19 gene
Two chemically close transcription factors, angiotensin-converting enzyme (ACE2) in the intestine and renal
tubules, and collectrin in the renal tubules, are required for expression of B0AT1 transporter protein by the
The mutated gene in patients with Hartnup disorder, unable to interact with the above transcription factors,
results in deficiency of B0AT1 protein either in the intestine or in the renal tubules or in both
Cutaneous Photosensitivity is the most common presenting complaint.
Intermittent Ataxia manifested as unsteady wide based gait.
Pellagra like Symptoms