The article derives the probability for lethal recessive alleles in the case of recessive disadvantage or advantage. It is shown that the recessive advantage of a lethal gene can be detected by the ratio of heterozygotes and homozygotes. This demonstrates that the higher IQ of certain ethnic groups cannot be explained by the recessive advantage of lethal genes. The article shows that lethal genes can survive in the population if some lineages of families have much more children than the average.

Retinitis pigmentosa (RP) clinically and genetically heterogeneous group of inherited retinal disorders (IRD) that result in retinal degeneration. This study aimed to identify the genetic findings of patients with autosomal recessive retinitis pigmentosa (arRP). Whole exome sequencing (WES) was performed in two unrelated Pakistani families underlying arRP. Data analysis and mutation screening was performed for all the known RP genes following bi-directional Sanger sequencing to determine whether any of the candidate variants co-segregated with the disease phenotype in the families. WES data analysis revealed a novel homozygous missense variant (c.1274T>C) in the in Tubby like Protein 1 (TULP1 NM_003322.6) gene in family 1 and a novel homozygous frameshift variant (c.351delC) in the retinoid isomerohydrolase 65 (RPE65 NM_000329.3) gene in family 2. The identified variants perfectly co-segregated with the disease phenotype within the families. Our results strongly suggest that mutations in TULP1 and RPE65 are responsible for the retinal phenotype in the affected individuals. These mutations will increase the mutation spectrum of these genes; furthermore, it will enhance our knowledge and understanding of the underlying molecular mechanisms of retinitis pigmentosa.

Introduction: Parkinson’s disease (PD) patients harboring recessive gene variants exhibit a distinct clinical phenotype with an early disease onset and relatively mild symptoms. Data concerning individualized therapy for autosomal recessive PD forms are still scarce. Methods: Demographic and treatment data of a cohort of PD carriers of recessive genes (9 homozygous or compound heterozygous PRKN carriers, 4 Heterozygous PRKN carriers and 3 biallelic PINK1 carriers) were evaluated. Results: The average Levodopa Equivalent daily dose (LEDD) was 806.8±453.5 (range 152-1810) in PRKN carriers and 765±96.6 (range 660-850) in PINK1 carriers. The majority responded to low/moderate doses of Levodopa. The response to Dopamine Agonists (DA) was often favorable both as initial and longitudinal therapy. 8/13 PRKN and 1/3 PINK1 carriers were treated with amantadine successfully, and this also applied to patients who could not tolerate Levodopa or DA. Conclusions: In the era of personalized treatment, the therapeutic approach in recessive PD gene carriers might differ as compared to idiopathic PD. Lower LEDD doses were efficient even in patients with a very long disease duration, while a few patients were doing well without any Levodopa treatment decades after disease initiation. DA or amantadine could be used as a first and main line treatment regimen if well tolerated. Literature data on therapeutic strategies in carriers of pathogenic mutations in recessive PD genes, including device-aided treatments will be further discussed.

Mitochondrial Encephalohepatopathy (MEH) is an autosomal recessive neurodevelopmental disorder usually accompanied by microcephaly, white matter changes, cardiac and hepatic failure. Here, we applied the whole-exome sequencing (WES) framework on a trio family data with unaffected non-consanguineous parents and proband (neonate girl) with this inherited disorder. A total of 2,928,402 variants were observed with 2,613,746 SNPs, 112,336 multiple nucleotide polymorphisms (MNPs), 72,610 insertions, 113,207 deletions and 16,503 mixed variants. These variations are responsible for 82,813,631 effects on various genomic regions. Our pipeline uncovered candidate gene mutations from these variants and retained a handful of 5,277 variants harboring 3,598 genes, out of which, 8 genes codes for non-coding RNA while 178 genes are those with high impact severity. Among these 178 variants, 125 are de-novo variants that are not previously reported in the ClinVar database. Consistent to previous studies, the leftover high impact severity genes are involved in encephalopathy, Leigh syndrome, Charcot–Marie–Tooth disease, global developmental disorder, seizures, spastic paraplegia, premature ovarian failure, mitochondrial myopathy-cerebellar, ataxia-pigmentary, retinopathy syndrome, ocular and retinal degeneration, deafness, intellectual disability, cardiofacioneurodevelopmental syndrome etc. All these clinical features were also observed in the patient studied. The current analysis highlights and expands the genetic architecture of the MEH phenotype. Furthermore, this pipeline on trio family data significantly broadens the concept of its usefulness as a first-tier diagnostic method in the detection of complex multisystem phenotypic disorders.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare severe hereditary skin disease characterized by skin and mucosa fragility, resulting in blister formation. The most severe complication in RDEB patients is the development of cutaneous squamous cell carcinoma (SCC) leading to premature death. Multiple evidences suggest a permissive tumor micro-environment (TME) as driver of SCC development in RDEB patients. In a cohort of RDEB patients, we characterized the immune profiles of RDEB-SCCs and compared them with clinical, histopathological, and prognostic features. RDEB-SCCs were subdivided into 4 groups based on their occurrence (first onset or recurrences) and grading according to their clinical-histopathological parameters of aggressiveness. Thirty-eight SCCs from 20 RDEB patients were analysed. Five RDEB patients experienced an unfavorable course af-ter the diagnosis of the first SCC, with early recurrence or metastasis, whereas 15 pa-tients developed multiple SCCs without metastasis. High-risk primary RDEB-SCCs showed a higher neutrophil-to-lymphocyte ratio in the tumor microenvironment, and an increased proportion of neutrophil extracellular traps (NET). Additionally, citrullinated histone H3, a marker of NETs, was increased in the serum of RDEB patients with high-risk primary SCC, suggesting that this modified form of histone H3 may serve as a potential blood marker of unfavorable prognosis in RDEB-SCCs.

An in-silico WES approach using the Galaxy platform was adopted in the current study to predict the genetic basis of Premature Ovarian Failure (POF), where three affected patients in a Saudi Arabian family of seven, found associated with X-linked recessive mutations. The current analysis discovered 518,054 variants using FreeBayes variant caller that had 1,461,864 effects on variable sites in the genome revealed by SnpEff software. The causal genetic mutations were filtered and annotated with the ClinVar database using the GEMINI tool. This tool retained 369 pathogenic mutations harboring 130 genes. Among the total, 268 variants positioned on 69 genes are shared with three affected individuals, 61 variants on 23 genes are shared by any two of the affected individuals, and 40 of the variants on 38 genes are present in any one of the affected sample. Two mutations in one of the already POF-associated, POF1B gene were also observed e.g. (i) g.84563135T>A; p.M349L and (ii) g.84563194C>T; p.R329Q in the two affected individuals i.e. IV-I-C & IV-6 in the current data. This gene consists of 17 exons that span the region of >100 kb. The putative function of this gene in regulating the actin cytoskeleton due to homology with myosin tail and maintains a number of oocytes during fetal ovary development. In a nutshell, this Galaxy pipeline facilitates all-in-one to pinpoint not only the known pathogenic gene mutations for this disorder but few other novel genetic variants as well, whose gene-disease association may be validated by further experimental studies.

Recessive dystrophic epidermolysis (RDEB) is a rare, inherited and currently incurable skin blistering disorder characterized by cyclically recurring wounds coexisting with chronic non-healing wounds. In a recent clinical trial three intravenous infusions of skin-derived ABCB5+ mesenchymal stromal cells (MSCs) to 14 patients with RDEB improved healing of wounds that were present at baseline. Since in RDEB even minor mechanical forces perpetually provoke the development of new or recurrent wounds, a post-hoc analysis of patient photographs was performed to specifically assess the effects of ABCB5+ MSCs on new or recurrent wounds by evaluating 174 wounds that occurred after baseline. During 12 weeks of systemic treatment with ABCB5+ MSCs the number of newly occurring wounds declined. When compared to the previously reported healing responses of the wounds present at baseline, the newly occurring wounds healed faster, and a greater portion of healed wounds remained stably closed. These data suggest a previously undescribed skin-stabilizing effect of treatment with ABCB5+ MSCs and support repeated dosing of ABCB5+ MSCs in RDEB to continuously slow the wound development and accelerate the healing of new or recurrent wounds before they become infected or progress to a chronic, difficult-to-heal stage.

This study aimed to identify whether gyrate atrophy of the choroid and retina (GACR) heterozygous individuals have possible clinical manifestations and to explore the potential pathogenic mechanism. In this retrospective study, we surveyed a two-generation pedigree of an individual diagnosed with GACR. Two family members underwent ophthalmological, hematologic, and genetic tests. An arginine-restricted diet with vitamin B6 supplementation was implemented; clinical assessments were repeated every 3 months during follow-up. Relative OAT mRNA expression was determined using real-time quantitative polymerase chain reaction. The 19-year-old compound heterozygous daughter (OAT: c.1186C>T; c.748C>T), had bilateral high myopia, posterior staphyloma, chorioretinal atrophy, macular abnormalities, and elevated hematologic ornithine. The 54-year-old heterozygous mother (OAT: c.1186C>T), presented with bilateral severe myopia, asymmetric posterior staphyloma, retina and choroidal capillary layer atrophy, retinal pigment epithelium abnormalities, and mildly elevated hematologic ornithine. Compared to normal individuals, the daughter and mother had 29% and 46% relative OAT mRNA expression, respectively (P<0.001). We believe that this is the first report of a carrier of one OAT variant allele with mild phenotypes, suggesting that family members should be aware of the possible involvement of autosomal recessive conditions. Additional data suggests nonsense mediated decay-initiated mRNA degradation may cause GACR.

Mutations in the SACS gene are associated with autosomal recessive spastic ataxia of Charlevoix-Saguenay disease (ARSACS) or complex clinical phenotypes of Charcot-Marie-Tooth disease (CMT). This study aimed to identify SACS mutations in a Korean CMT cohort with cerebellar ataxia and spasticity. As a result, eight pathogenic SACS mutations in four families were identified as the underlying causes of these complex phenotypes. The prevalence of CMT families with SACS mutations was determined to be 0.3%. All the patients showed sensory, motor, and gait disturbances with increased deep tendon reflexes. Lower limb magnetic resonance imaging (MRI) was done in four patients, and all had fatty replacements. Of note, they all had similar fatty infiltrations between the proximal and distal lower limb muscles, different from the neuromuscular imaging feature in most CMT patients without SACS mutations who had distal dominant fatty involvement. Therefore, these findings were considered a characteristic feature in CMT patients with SACS mutations. Although further studies with more cases are needed, our results highlight lower extremity MRI findings in CMT patients with SACS mutations and broaden the clinical spectrum. We suggest screening for SACS in recessive CMT patients with complex phenotypes of ataxia and spasticity.

Dysferlinopathies comprise a spectrum of muscular dystrophies characterized by progressive muscle weakness and degeneration due to mutations in the DYSF gene, which encodes the dysferlin protein critical for muscle membrane repair. This review delves into the clinical spectra of dysferlinopathies, their molecular mechanisms, and the spectrum of emerging therapeutic strategies. We explore the phenotypic heterogeneity of dysferlinopathies, highlight the incomplete understanding of genotype-phenotype correlations, and discuss the implications of various DYSF mutations. Furthermore, we examine the utility of animal models in elucidating disease mechanisms and the potential of symptomatic, pharmacological, molecular, and genetic therapies in mitigating the disease's progression. We also consider the roles of diet and metabolism in managing dysferlinopathies, as well as the impact of clinical trials on treatment paradigms. By culminating the complexities inherent in dysferlinopathies, this article emphasizes the need for multidisciplinary approaches, precision medicine, and extensive collaboration in research and clinical trial design to advance our understanding and treatment of these challenging disorders.