CRISPR/Cas9-Mediated Scanning for Regulatory Elements Required for HPRT1 Expression via Thousands of Large, Programmed Genomic Deletions.

The extent to which non-coding mutations contribute to Mendelian disease is a major unknown in human genetics. Relatedly, the vast majority of candidate regulatory elements have yet to be functionally validated. Here, we describe a CRISPR-based system that uses pairs of guide RNAs (gRNAs) to program thousands of kilobase-scale deletions that deeply scan across a targeted region in a tiling fashion ("ScanDel").

Self-injurious behavior.

Self-injurious behavior (SIB) is a relatively common behavior in individuals with intellectual disabilities (ID). Severe SIB can be devastating and potentially life-threatening. There is increasing attention for somatic substrates of behavior in genetic syndromes, and growing evidence of an association between pain and discomfort with SIB in people with ID and genetic syndromes.

Lesch-Nyhan disease in two families from Chiloé Island with mutations in the HPRT1 gene.

Lesch-Nyhan disease (LND) is a rare X-linked inherited neurogenetic disorder of purine metabolism in which the enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt) is defective. The authors report two independent point mutations leading to splicing errors: IVS 2 +1G>A, c.134 +1G>A, and IVS 3 +1G>A, c.

A Trivalent Enzymatic System for Uricolytic Therapy of HPRT Deficiency and Lesch-Nyhan Disease.

Purpose: Because of the evolutionary loss of the uricolytic pathway, humans accumulate poorly soluble urate as the final product of purine catabolism. Restoration of uricolysis through enzyme therapy is a promising treatment for severe hyperuricemia caused by deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT). To this end, we studied the effect of PEG conjugation on the activity and stability of the enzymatic complement required for conversion of urate into the more soluble (S)-allantoin.

Lesch-Nyhan syndrome: The saga of metabolic abnormalities and self-injurious behavior.

Lesch-Nyhan syndrome (LNS) is an X-linked recessive disorder of purine metabolism caused by a mutation in Xq26.2-q26.3 (OMIM 308000.

The renal phenotype of allopurinol-treated HPRT-deficient mouse.

Excess of uric acid is mainly treated with xanthine oxidase (XO) inhibitors, also called uricostatics because they block the conversion of hypoxanthine and xanthine into urate. Normally, accumulation of upstream metabolites is prevented by the hypoxanthine-guanine phosphoribosyltransferase (HPRT) enzyme. The recycling pathway, however, is impaired in the presence of HPRT deficiency, as observed in Lesch-Nyhan disease.

Quantification of various APP-mRNA isoforms and epistasis in Lesch-Nyhan disease.

The present work is the development of a simple and specific kinetic method based on RT-PCR technique coupled with direct sequencing for quantification of various amyloid precursor protein-mRNA isoforms (APP-mRNA isoforms) in biological samples, especially for identifying the most abundant one that may decisive for the normal status or disease risk. Application of this kinetic method to the Lesch-Nyhan disease (LND) was performed and results indicated an epistasis between mutated hypoxanthine phosphoribosyltransferase1 (HPRT1) and APP genes. APP-mRNA isoform of 624bp, with a deletion starting after 49bp of the 5' end of exon 3 followed by a complete deletion of exons 4-15, mutations in exon 1: c.

Oral Hemorrhage in a 3-year-old Boy Caused by Self-Mutilating Behavior.

A 3-year-old boy referred for persistent tongue bleeding was diagnosed with a rare self-mutilating disease that had also affected his lip and fingers. He underwent multiple odontectomy and partial glossectomy and continues to undergo behavior therapy and on-demand splints and restraints. He has stopped self-biting and has gained appetite and weight.

Human HPRT1 gene and the Lesch-Nyhan disease: Substitution of alanine for glycine and inversely in the HGprt enzyme protein.

Lesch-Nyhan disease (LND) is a rare X-linked inherited neurogenetic disorder of purine metabolism in which the enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt) is defective. The authors report three novel independent mutations in the coding region of the HPRT1 gene from genomic DNA of (a) a carrier sister of two male patients with LND: c.569G>C, p.

[Treatment of self-injurious behaviors in Lesch-Nyhan syndrome with S-adenosylmethionine].

An 11-year-old boy with Lesch-Nyhan syndrome (LNS) had persistently injured himself by biting his lips and buccal mucosa since infancy. Risperidone was only partially effective in suppressing this behavior. Oral administration of S-adenosylmethionine (SAMe), involving increasing the dose from 400 mg to 1 g, resulted in the amelioration of self-injurious behavior and anxiety as well as marked improvement in his self-esteem, performance at school, and friendships.

[Recent advances in urate metabolism].

In the last fifteen years, genomics and other -omics sciences have revolutionized our understanding of biological processes at the molecular level. An illustrative example is urate metabolism. Before the publication of the complete human genome, in 2003 it was believed that a single enzyme (urate oxidase) was responsible for uricolysis that is the conversion of urate into the more soluble allantoin.

Lesch-Nyhan Syndrome: Models, Theories, and Therapies.

Lesch-Nyhan syndrome (LNS) is a rare X-linked disorder caused by mutations in HPRT1, an important enzyme in the purine salvage pathway. Symptoms of LNS include dystonia, gout, intellectual disability, and self-mutilation. Despite having been characterized over 50 years ago, it remains unclear precisely how deficits in hypoxanthine and guanine recycling can lead to such a profound neurological phenotype.

A review of the implication of hypoxanthine excess in the physiopathology of Lesch-Nyhan disease.

Lesch-Nyhan disease is caused by HGprt deficiency, however, the mechanism by which enzyme deficiency leads to the severe neurological manifestations is still unknown. We hypothesized that hypoxanthine excess leads, directly or indirectly, through its action in adenosine transport, to aberrations in neuronal development. We found that hypoxanthine diminishes adenosine transport and enhances stimulation of adenosine receptors.

Development of new forms of self-injurious behavior following total dental extraction in Lesch-Nyhan disease.

We report two Lesch-Nyhan Disease (LND) patients who developed new forms of self-injurious behavior following total dental extraction. Patients 1 and 2 were submitted to total teeth extraction at the age of 13 and 8 years, respectively, due to continuous self-biting, not prevented by mouth guards. Severity of dystonia was markedly reduced and quality of life improved.

Self-injurious Behavior in a Young Child with Lesch-Nyhan Syndrome.

Lesch-Nyhan syndrome (LNS) is a rare inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase-1. Few reports on behavioral aspects especially self-injurious behavior in LNS patients are available. We report a case of LNS in an 8-year-old male child, who presented with characteristic self-injurious behavior.

Novel mutation in HPRT1 causing a splicing error with multiple variations.

Lesch-Nyhan disease (LND) is a rare X-linked recessive disorder caused by deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT), encoded by the HPRT1. To date, nearly all types of mutations have been reported in the whole gene; however, duplication mutations are rare. We here report the case of a 9-month-old boy with LND.

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.

Mutation in the Human HPRT1 Gene and the Lesch-Nyhan Syndrome.

Lesch-Nyhan syndrome (LNS) is a rare X-linked inherited neurogenetic disorder of purine metabolism in which the enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt) is defective. The authors report a novel mutation which led to HGprt-related neurological dysfunction (HND) in two brothers from the same family with a missense mutation in exon 6 of the coding region of the HPRT1 gene: c.437T>C, p.

Lesch-Nyhan Syndrome: Disorder of Self-mutilating Behavior.

Lesch-Nyhan syndrome (LNS), a rare inborn error of metabolism, is characterized by self-injurious behavior, which results in partial or total destruction of oral and perioral tissues and/ or fingers. Persistent self-injurious behavior (biting the fingers, hands, lips, and cheeks; banging the head or limbs) is a hallmark of the disease. Prevention of self-mutilation raises significant difficulties.

Towards rational drug treatment of Lesch-Nyhan disease.

Lesch-Nyhan disease (LND) is a rare X-chromosomal purine metabolism disorder. LND is characterized by self-injurious behavior (SIB) for which there is no drug treatment. This commentary places a recent clinical study by Khasnavis et al.

Neurotransmitter and their metabolite concentrations in different areas of the HPRT knockout mouse brain.

Lesch-Nyhan syndrome (LNS) is characterized by uric acid overproduction and severe neurobehavioral symptoms, such as recurrent self-mutilative behavior. To learn more about the pathophysiology of the disease, we quantified neurotransmitters and their metabolites in the cerebral hemisphere, cerebellum and the medulla oblongata of HPRT knockout mice, an animal model for LNS, in comparison to the corresponding wild-type. Our analyses included l-glutamate, 4-aminobutanoic acid (GABA), acetylcholine, serotonin, 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine, l-normetanephrine, epinephrine and l-metanephrine and were conducted via high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS).

Acute renal failure unmasking Lesch-Nyhan disease in a patient with tuberous sclerosis complex.

Case Report: We report on a male patient with Tuberous Sclerosis Complex (TSC), which was prenatally diagnosed. At the age of 3 months the patient developed acute renal failure with excessive hyperuricemia. Kidney function improved after rehydration and application of rasburicase, however without full recovery.

A double-blind, placebo-controlled, crossover trial of the selective dopamine D1 receptor antagonist ecopipam in patients with Lesch-Nyhan disease.

Lesch-Nyhan disease (LND) is a genetic disorder that has characteristic metabolic, neurologic, and behavioral features. There are multiple behavioral problems including impulsivity, aggressiveness, and severe recurrent self-injurious behavior (SIB). This last behavior varies considerably across subjects and may encompass self-biting, self-hitting, scratching, head banging, and other injurious actions.

Overcoming the oral aspects of -self-mutilation: description of a method.

Background/aim: Self-injurious behavior (SIB) is a serious and chronic condition frequently seen in special needs populations, affecting 10% to 17% of individuals diagnosed with intellectual and/or developmental disabilities. A 2.5-year-old infant with SIB, whose presenting symptoms were severe tongue and lip lacerations accompanied by much hemorrhage, is presented here to illustrate the problem and to show how this may be prevented.