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Background: Autosomal recessive forms of retinitis punctata albescens (RPA) have been described. RPA is characterized by progressive retinal degeneration due to alteration in visual cycle and consequent deposit of photopigments in retinal pigment epithelium. Five loci have been linked to RPA onset. Among these, the retinaldehyde-binding protein 1 gene, RLBP1, is the most frequently involved and several founder mutations were reported. We report results of a genetic molecular investigation performed on a large Sicilian family in which appears a young woman with RPA. Results: The proband is in homozygous condition for a novel RLBP1 single-pair deletion, and her healthy parents, both heterozygous, are not consanguineous. Thenovelc.398delC (p.P133Qfs*258) involves the exon 6 and leads to a premature stop codon, resulting in a truncated protein entirely missing of CRAL-TRIO lipid-binding domain. Pedigree analysis showed other non-consanguineous relatives heterozygous for the same mutation in the family. Extension of mutation research in the native town of the proband revealed its presence also in healthy subjects, in a heterozygous condition. Conclusions: A novel RLBP1 truncating mutation was detected in a young girl affected by RPA. Although her parents are not consanguineous, the mutation was observed in a homozygous condition. Being them native of the same small Sicilian town of Fiumedinisi, the hypothesis of a geographical area-related mutation was assessed and confirmed. [ABSTRACT FROM AUTHOR]

Background: Cerebral cavernous malformations (CCMs) are vascular anomalies of the nervous system mostly located in the brain presenting sporadically or familial. Causes of familial forms are mutations in CCM1 (Krit1), CCM2 (MGC4607) and CCM3 (PDCD10) genes. Sporadic forms with no affected relative most often have only one lesion and no germ line mutations. However, a number of sporadic cases with multiple lesions have been reported and are indeed genetic cases with a de novo mutation or a mutation inherited from an asymptomatic parent. Methods: Here, we performed an analysis of regulatory region of CCM genes in 60 sporadic patients, negative for mutations in coding region and intron-exon boundaries and large deletion/duplications in CCM genes by direct sequencing and MLPA. Among 5 variants identified in 851-bp region shared by CCM3 and SERPINI1 genes and acting as asymmetric bidirectional promoter, two polymorphisms c.-639 T > C/rs9853967 and c.-591 T > C/rs11714980 were selected. A case-control study was performed to analyze their possible relationships with sporadic CCMs. Promoter haplotypes activities on CCM3/SERPINI1 genes expression were tested by dual-luciferase assay. Results: No variants were identified in CCM1 and CCM2 regulatory regions. In CCM3/SERPINI1 asymmetric bidirectional promoter 5 variants, 2 of them unknown and 3 corresponding to polymorphisms c.-639 T > C/rs9853967, c.-591 T > C/rs11714980 and c.-359G > A/rs9834676 were detected. While rs9853967 and rs11714980 polymorphisms fall in a critical regulatory fragment outside the minimal promoter in intergenic region, other variants had no effects on transcription factor binding according to RegRNA tool. Case-control study performed on 60 patients and 350 healthy controls showed frequencies of the mutated alleles significantly higher in the control group than in patients. Furthermore, the functional assay showed a significant reduction of CCM3 expression for C-C haplotype even more than for T-C and C-T haplotypes. In SERPINI1 direction, the reduction was not statistically significant. Conclusions: Our data indicated that rs9853967 and rs11714980 polymorphisms could be associated with a protective role in CCM disease. [ABSTRACT FROM AUTHOR]

Introduction: Trimethylaminuria is a rare inherited disorder due to decreased metabolism of dietary-derived trimethylamine by flavin-containing monooxygenase 3. Several single nucleotide polymorphisms of the flavin-containing monooxygenase 3 gene have been described and result in an enzyme with decreased or abolished functional activity for trimethylamine N-oxygenation thus leading to trimethylaminuria.Case Presentation: Here we investigated an Italian family in which the proband was a 7-year-old girl with suspected trimethylaminuria, by flavin-containing monooxygenase 3 gene direct sequencing and urinary determination of trimethylamine and trimethylamine N-oxide. Genetic analysis found that, as with her parents and one of her two brothers, the proband carried three polymorphisms: c.472 G>A p. E158K (rs 2266782) in exon 4, c.627+10 C>G (IVS5+10G>C) (rs 2066534) and c.485-21 G>A (IVS4-22G>A) (rs 1920149) in intronic regions.Conclusions: Despite the same genotypic condition only the girl had symptoms attributable to the trimethylaminuria. The suspicion is that she has transient childhood trimethylaminuria. Therefore, we bring attention to the importance of genetic testing and eventual determination of urinary trimethylamine and trimethylamine N-oxide as instruments to offer to clinicians in the management of these pediatric patients. [ABSTRACT FROM AUTHOR]