Four novel RS1 gene mutations in Polish patients with X-linked juvenile retinoschisis.

PURPOSE: To determine the clinical features and to identify mutations in the retinoschisis gene (RS1) in ten patients with X-linked retinoschisis (XLRS). METHODS: Ten male patients from nine Polish families were included in this study. Ophthalmologic examinations, including optical coherence tomography (OCT) and full-field electroretinography (ERG), were performed in all affected boys. The entire coding region encompassing six exons of the RS1 gene was amplified with PCR and directly sequenced in all the patients. RESULTS: All affected individuals showed typical retinoschisis signs and symptoms, and all appeared to have a mutation in the RS1 gene. Seven different mutations were identified, including two novel missense substitutions: c.176G>C (p.Cys59Ser), c.451T>A (p.Tyr151Asp); one novel nonsense substitution: c.218C>A (p.Ser73*); and one novel frameshift mutation: c.354_355delCA (p.Asp118Glufs*2). We also found two missense substitutions that had been previously described: c.214G>A (p.Glu72Lys) and c.626G>T (p.Arg209Leu) and one known splice site mutation in intron 5: c.522+1G>T (IVS5+1G>T). CONCLUSIONS: This study provides the first molecular genetic characteristics of patients with juvenile retinoschisis from the previously unexplored Polish population. We investigated the molecular background of XLRS in ten boys. The present study reports for the first time four novel mutations, including two missense substitutions, one nonsense substitution, and one frameshift deletion. One of these substitutions and 2-bp deletion created stop codons. Moreover, we described three substitutions that had been previously reported (one is a splicing mutation). Further genetic characterization of Polish patients with XLRS will be helpful in understanding the worldwide spectrum of RS1 mutations. Despite the mutation heterogeneity found in a small group of our patients, they presented a relatively uniform clinical picture. Identifying the causative mutation is helpful in confirming diagnosis and counseling, but cannot provide prognostic data.

A comparative analysis of MC4R gene sequence, polymorphism, and chromosomal localization in Chinese raccoon dog and Arctic fox.

Numerous mutations of the human melanocortin receptor type 4 (MC4R) gene are responsible for monogenic obesity, and some of them appear to be associated with predisposition or resistance to polygenic obesity. Thus, this gene is considered a functional candidate for fat tissue accumulation and body weight in domestic mammals. The aim of the study was comparative analysis of chromosome localization, nucleotide sequence, and polymorphism of the MC4R gene in two farmed species of the Canidae family, namely the Chinese raccoon dog (Nycterutes procyonoides procyonoides) and the arctic fox (Alopex lagopus). The whole coding sequence, including fragments of 3'UTR and 5'UTR, shows 89% similarity between the arctic fox (1276 bp) and Chinese raccoon dog (1213 bp). Altogether, 30 farmed Chinese raccoon dogs and 30 farmed arctic foxes were searched for polymorphisms. In the Chinese raccoon dog, only one silent substitution in the coding sequence was identified; whereas in the arctic fox, four InDels and two single-nucleotide polymorphisms (SNPs) in the 5'UTR and six silent SNPs in the exon were found. The studied gene was mapped by FISH to the Chinese raccoon dog chromosome 9 (NPP9q1.2) and arctic fox chromosome 24 (ALA24q1.2-1.3). The obtained results are discussed in terms of genome evolution of species belonging to the family Canidae and their potential use in animal breeding.

Polymorphisms in 5'-flanking regions of genes encoding adiponectin, leptin, and resistin are not associated with obesity of Polish children and adolescents.

Genes encoding adipokines are important functional candidates for development of obesity. In this study we screened for polymorphism 5'-flanking regions of the adiponectin (ADIPOQ), leptin (LEP) and resistin (RETN) genes in a cohort of Polish obese children and adolescents (n = 243) and a control group of non-obese adults (n = 100). Altogether 13 SNPs (single nucleotide polymorphisms) and 1 InDel (insertion/deletion polymorphism) were found. Among them five polymorphisms, localized in the LEP gene, turned out to be novel, but their distribution was insufficient for association studies. We found no consistent evidence for association between obesity and the SNPs demonstrating minor allele frequency (MAF) above 0.2 (ADIPOQ: -11377C>G, LEP: -2548C>T, 19A>G, RETN: -1300G>A, -1258C>T, -420C>G). Comparison of polymorphisms distribution in patients and control group suggested association with ADIPOQ -11377C>G (Pearson test P = 2.76 × 10(-11)), however, we did not observe any effect of this polymorphism on BMI or relative BMI (RBMI) within obese patients (P = 0.41). We conclude that the tested SNPs are not useful markers of childhood and adolescence obesity in Polish population.

Polymorphism and chromosomal location of the MC4R (melanocortin-4 receptor) gene in the dog and red fox.

The melanocortin-4 receptor (MC4R) is expressed in the hypothalamus and regulates energy intake and body weight. In silico screening of the canine chromosome 1 sequence and a comparison with the porcine MC4R sequence by BLAST were performed. The nucleotide sequence of the whole coding region and 3'- and 5'-flanking regions of the dog (1214 bp) and red fox (1177 bp) MC4R gene was established and high conservation of the nucleotide sequences was revealed (99%). Five sets of PCR primers were designed and a search for polymorphism was performed by the SSCP technique in a group of 31 dogs representing nineteen breeds and 35 farm red foxes. Sequencing of DNA fragments, representing the identified SSCP patterns, revealed three single nucleotide polymorphisms (including a missense one) in dogs and four silent SNPs in red foxes. An average SNP frequency was approx. 1/400 bp in the dog and 1/300 bp in the red fox. We mapped the MC4R gene by FISH to the canine chromosome 1 (CFA1q1.1) and to the red fox chromosome 5 (VVU5p1.2).

Robertsonian translocation (8;14) in an infertile bitch (Canis familiaris).

A new case of a Robertsonian translocation diagnosed in an infertile bitch of West Highland White Terrier breed is reported. Cytogenetic analyses were performed with the use of Giemsa staining, Q-, C- and Ag-I banding techniques and FISH with canine whole X chromosome paint. The karyotype of this bitch was described as 77,XX der (8;14)(q10;q10).