Hydroxykynureninuria

What it is

A rare, genetic disorder of tryptophan metabolism characterized by massive urinary excretion of xanthurenic acid (XA), 3-hydroxykynurenine and kynurenine and increased XA concentration in plasma. The clinical phenotype is highly variable, ranging from asymptomatic or mild cases presentating with jaundice and vomiting, with subsequent normal development and growth, to more severe cases with manifestions which include intellectual disability, cerebellar ataxia, pellagra, progressive encephalopathy with muscular hypotonia, global developmental delay, stereotyped gestures and/or congenital deafness.

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Infancy, Neonatal

Inheritance

Autosomal recessive

Classified as

Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

Gene

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references