Severe persistent unremitting dermatitis, chronic diarrhea and hypoalbuminemia in a child; Hartnup disease in setting of celiac disease

New aspects for the brain in Hartnup disease based on mining of high-resolution cellular mRNA expression data for SLC6A19

Hartnup disease is an autosomal recessive, metabolic disorder caused by mutations of the neutral amino acid transporter, SLC6A19/B0AT1. Reduced absorption in the intestine and kidney results in deficiencies in neutral amino acids and their down-stream metabolites, including niacin, associated with skin lesions and neurological symptoms. The effects on the nervous system such as ataxia have been related to systemic deficiencies of tryptophan (and other neutral amino acids) as no expression of the B0AT1 transporter was found in the brain. In the intestine, SLC6A19 cooperates with ACE2 which has received major attention as the cellular receptor for SARS-CoV-2. When transcriptomics data for ACE2 and its partner proteins were examined, a previously unrecognized expression of Slc6a19 mRNA in the ependymal cells of the mouse brain was encountered that is set into the context of neurological manifestations of Hartnup disease with this communication. A novel role for SLC6A19/B0AT1 in amino acid transport from CSF into ependymal cells is proposed and a role of niacin in ependymal cells highlighted.

Sailing the ship of life: scurvy and autoimmunity

Celiac disease (CD) is a multisystem disorder known to manifest in a multitude of ways to include diarrhea, anemia, and nutritional deficiencies. The malabsorptive state can present as certain classical conditions such as autoimmune gastritis and osteopenia/osteoporosis but scurvy is less recognized within the literature. In this case, we present a unique presentation of scurvy as a result of an undiagnosed CD.

Pellagra secondary to selective eating in a child with autism

Once a significant cause of morbidity and mortality, health care providers rarely see primary pellagra in developed countries where fortification of foods with niacin is commonplace and niacin-rich foods are generally widely available. We report a ten-year-old boy with autism spectrum disorder who presented with photosensitive dermatitis which resolved after vitamin supplementation and dietary changes. In this child, the pellagra developed as the result of a long-term pattern of selective eating. Restricted diets, even to the point of nutrient deficiencies, are well-documented among children with autism spectrum disorders (ASD).

Study of Seizure-Manifested Hartnup Disorder Case Induced By Novel Mutations in SLC6A19

AIM

The aim of the study is to investigate a variation in the gene SLC6A19 in a female patient with Hartnup disorder manifested only by seizure.

METHODS

DNA samples collected from the patient and her parents were analyzed and twelve exons of the SLC6A19 gene were amplified and sequenced.

RESULTS

We found c.47C>T and c.1522G>A mutations in the gene SLC6A19 belonging to the patient, which are missense mutations inherited from her parents. The c.47C>T mutation is from her father and c.1522G>A is inherited from her mother. The parents are both heterozygous healthy carriers.

CONCLUSION

Two novel mutations of the SLC6A19 gene are revealed in the female patient with Hartnup disorder, exhibiting no typical dermatologic problems, but having dramatic neurological symptoms.