HPRTYale proposed as a pathogenic variant for Lesch-Nyhan syndrome: a case report.

Lesch-Nyhan syndrome (LNS) is an X-linked recessive disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT), an enzyme encoded by the HPRT1 gene. The classic disease phenotype described by Lesch and Nyhan in 1964 includes hyperuricemia, mental retardation, severe motor deficiency, and recurring self-mutilation. Here, we report the case of a family with 4 affected males and several female obligate carriers. In 1989, Fujimori et al. reported on a patient diagnosed with LNS who had an HPRT variant thereafter codenamed HPRTYale. The same patient was studied by Wilson et al. in 1986, who found no detectable HPRT enzymatic activity, even though normal HPRT mRNA and protein levels were observed. Disease severity is closely related to residual enzymatic activity, which fits the phenotype presented for this previously reported case, as well as for the patients we report on herein. As it has been reported in only one patient, this mutation is still considered a variant of unknown significance. The HPRTYale mutation is a G>C transversion that leads to a different amino acid with different biochemical properties at position 71, potentially causing the major lack of function. To evaluate the impact of this variant, we used the PolyPhen-2 software, which classified it as possibly damaging. Furthermore, the frequency of this mutant allele is likely extremely rare, since it has only been reported on twice, and a population frequency is not yet available. In conclusion, we propose that the HPRTYale variant is pathogenic, and should be included on lab reports hereafter.

Hypoxanthine-guanine phosphoribosyltransferase deficiency in a patient with a Madrid II mutation.

The hypoxanthine-guanine phosphoribosyltransferase deficiency is an inborn error of purine metabolism, linked to the X chromosome. The clinical phenotypes associated with HPRT deficiency varied according to the level of enzyme deficiency, with a large spectrum of neurologic features like self-injurious behaviour in patients with complete deficiency. We report a 20-year-old man who had asymmetric polyarthritis, tophi, hyperuricemia, nephrolithiasis and mild neurologic symptoms with undetectable levels of HPRT activity in lysed erythrocytes. The genetic study identified the c.143G>A mutation in exon 3, GAA CGT (CTT>GAA CAT CTT (48arg>his). The presence of gouty arthropathy and chronic hyperuricemia in a young patient with neurological symptoms, suggests HPRT deficiency for which it is necessary its enzyme and molecular determination.

Identification of a new lesch syndrome mutation (HPRT BRASIL) and analysis of pontentially heterozygous females

The mutation in the hypoxanthine-guanine phosphoribosyltransfere (HPRT) gene has been determined in two brothers affected with Lesch-Nyhan syndrome. Female members of the family who are at risk for being heterozygous carriers of the HPRT mutation were also studied to determine whether they carry the mutation. DNA sequencing revealed that the boys' mother heterozygous for the mutation in her somatic cells, but that three maternal aunts are not heterozygous. Such carrier information is important for the future pregnancy plans of at-risk females. The mutation, an A_T transversion at cDNA base 590 (590 A_T), results in an amino acid change of glutamic acid to valine at codon 197, and has not been reported previously in a Lesch-Nyhan syndrome male. This mutation is designated HPRT.

Identification of a new Lesch-Nyhan syndrome mutation (HPRTBrasil) and analysis of potentially heterozygous females.

The mutation in the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene has been determined in two brothers affected with Lesch-Nyhan syndrome. Female members of the family who are at risk for being heterozygous carriers of the HPRT mutation were also studied to determine whether they carry the mutation. DNA sequencing revealed that the boys' mother is heterozygous for the mutation in her somatic cells, but that three maternal aunts are not heterozygous. Such carrier information is important for the future pregnancy plans of at-risk females. The mutation, an A-->T transversion at cDNA base 590 (590A-->T), results in an amino acid change of glutamic acid to valine at codon 197, and has not been reported previously in a Lesch-Nyhan syndrome male. This mutation is designated HPRTBrasil.

Sindrome de Lesch-Nyhan. Revisión de la literatura y reporte de un caso / Lesch-Nyhan syndrome. Review of the literature and report of a case

El sindrome de Lesch-Nyhan es una enfermedad congénita poco común, caracterizada por la automutilación de dedos y tejidos blandos bucales principalmente. En el presente artículo se describe el caso clínico de un paciente de 6 años de edad con este padecimiento así como el tratamiento estomatológico efectuado

Síndrome de Lesch-Nyhan incompleto : comunicación del primer caso argentino / Incomplete Lesch-Nyhan syndrome : communication of first case argentinian

El síndrome de Lesch-Nyhan es una infrecuente gota hereditaria vinculada al déficit virtualmente completo de la enzima hipoxantina guanina fosforribosil transferasa (HGFT) existiendo ocasionalmente déficit parciales, que se diferencian de las formas completas por presentar manifestaciones neuropsiquiátricas menores. Es nuestro objetivo presentar al que en nuestro conocimiento es el primer paciente argentino portador del síndrome de Lesh-Nyhan incompleto o de Kelley-Seegmiller. Paciente varón de 38 años con historia familiar de gota e insuficiencia renal que desarrolla una severa artritis gotosa tofácea de rápida evolución y déficit intelectual. Los análisis de laboratorio de rutina mostraron una marcada hiperuricemia y excesiva excreción de ácido úrico con una función renal conservada. La determinación de la actividad enzimática de la HGFT se halló francamente disminuida.

Síndrome de Lesch-Nyhan incompleto : comunicación del primer caso argentino / Incomplete Lesch-Nyhan syndrome : communication of first case argentinian

El síndrome de Lesch-Nyhan es una infrecuente gota hereditaria vinculada al déficit virtualmente completo de la enzima hipoxantina guanina fosforribosil transferasa (HGFT) existiendo ocasionalmente déficit parciales, que se diferencian de las formas completas por presentar manifestaciones neuropsiquiátricas menores. Es nuestro objetivo presentar al que en nuestro conocimiento es el primer paciente argentino portador del síndrome de Lesh-Nyhan incompleto o de Kelley-Seegmiller. Paciente varón de 38 años con historia familiar de gota e insuficiencia renal que desarrolla una severa artritis gotosa tofácea de rápida evolución y déficit intelectual. Los análisis de laboratorio de rutina mostraron una marcada hiperuricemia y excesiva excreción de ácido úrico con una función renal conservada. La determinación de la actividad enzimática de la HGFT se halló francamente disminuida. (AU)

Aspectos clínicos y bioquímicos del síndrome de Lesch-Nyhan

El síndrome de Lesch-Nyhan es una enfermedad genética ligada al cromosoma X, originada por un defecto en el gen que codifica la hipoxantia guanina fosforribosiltransferasa (HGPRT). Esta enzima participa en la recuperación de la guanina e hipoxantina. La deficiencia enzemática conlleva una acumulación exagerada del ácido úrico. La deficiencia total o casi total de la enzima, produce el síndrome de Lesch-Nyhan, el cual se caracteriza por hiperruricemia, hiperaciduria, coreoatetosis, hiperreflexia, retardo mental y autoagresividad. La deficiencia parcial de la enzima ocasiona artritis gotosa y nefrolitiasis sin daño neurológico.

[Lesch-Nyhan syndrome. Report of a case]. / Síndrome de Lesch-Nyhan. Informe de un caso.

A case is reported with a syndrome characterized by mental retardation, choreoathetosis, high levels of uric acid and aggressive, selfmutilation behavior, diagnosed as Lesch-Nyhan's syndrome. The most important features are, its appearance confined only to males, the absence of abnormalities along the prenatal and newborn periods, as well as the progressive impairment in the clinical course of the patient. The presence of high blood levels of uric acid which was controlled with the administration of allopurinol, the anemia, treated with ferrous sulfate and the complete absence of the AGPRT enzyme, were the laboratory findings. The clinical, pathophysiological and biochemical aspects of the treatment were also reviewed, as well as the experiences and findings reported in other series. The authors stress the very low frequency of these cases, the importance of making the diagnosis and the exceptional and eccentricity of the features which are part of the syndrome, such as the bites.