hydroxykynureninuria; xanthurenic aciduria; kynureninase deficiency

Epidemiology

• rare

Pathology

• abnormality of tryptophan metabolism
• deficiency of kynureninase

Genetics

• autsomal recessive
• defect in KYNU (kynureninase)

Clinical manifestations

• anemia
• diarrhea
• headache (severe, recurrent or occipital, migraine)
• hearing defect, deafness
• hepatomegaly
• splenomegaly
• mental retardation
• photophobia or photosensitive defect in light-exposed area
• stomatitis

Laboratory

• urine xanthurenate is elevated
• urine kynurenine is elevated
• urine 3-hydroxykynurenine is elevated

Management

• vitamin B6

More general terms

• inborn error of metabolism
• enzyme deficiency

Additional terms

• kynureninase; L-kynurenine hydrolase (KYNU)
• kynurenine pathway