Non-type I cystinuria associated with mental retardation and ataxia in a Korean boy with a new missence mutation(G173R) in the SLC7A9 gene.

[cystinuria]

Cystinuria is an inherited renal and intestinal disease characterized by defective amino acids reabsorption and cystine urolithiasis . It is unusually associated with neurologic symptoms . Mutations in two genes , SLC 3 A 1 and SLC 7 A 9 , have been identified in cystinuric patients . This report presents a 13 -yr -old boy with cystinuria who manifested difficulty in walking , ataxia , and mental retardation . Somatosensory evoked potential of posterior tibial nerve stimulation showed the central conduction dysfunction through the posterior column of spinal cord . He was diagnosed non-type I cystinuria by urinary amino acid analysis and oral cystine loading test . We screened him and his family for gene mutation by direct sequencing of SLC 3 A 1 and SLC 7 A 9 genes . In this patient , we identified new missence mutation G 173 R in SLC 7 A 9 gene .

Diseases
Validation

Diseases presenting "mental retardation" symptom

achondroplasia

alexander disease

alpha-thalassemia

aniridia

aromatase deficiency

canavan disease

classical phenylketonuria

coats disease

cohen syndrome

cowden syndrome

cystinuria

dentin dysplasia

familial hypocalciuric hypercalcemia

homocystinuria without methylmalonic aciduria

hydrocephalus with stenosis of the aqueduct of sylvius

kabuki syndrome

kallmann syndrome

lamellar ichthyosis

lymphangioleiomyomatosis

monosomy 21

phenylketonuria

primary hyperoxaluria type 1

proteus syndrome

pyruvate dehydrogenase deficiency

sneddon syndrome

triple a syndrome

wolf-hirschhorn syndrome

zellweger syndrome

This symptom has already been validated