Biallelic mutations in neurofascin cause neurodevelopmental impairment and peripheral demyelination.

Axon pathfinding and synapse formation are essential processes for nervous system development and function. The assembly of myelinated fibres and nodes of Ranvier is mediated by a number of cell adhesion molecules of the immunoglobulin superfamily including neurofascin, encoded by the NFASC gene, and its alternative isoforms Nfasc186 and Nfasc140 (located in the axonal membrane at the node of Ranvier) and Nfasc155 (a glial component of the paranodal axoglial junction). We identified 10 individuals from six unrelated families, exhibiting a neurodevelopmental disorder characterized with a spectrum of central (intellectual disability, developmental delay, motor impairment, speech difficulties) and peripheral (early onset demyelinating neuropathy) neurological involvement, who were found by exome or genome sequencing to carry one frameshift and four different homozygous non-synonymous variants in NFASC. Expression studies using immunostaining-based techniques identified absent expression of the Nfasc155 isoform as a consequence of the frameshift variant and a significant reduction of expression was also observed in association with two non-synonymous variants affecting the fibronectin type III domain. Cell aggregation studies revealed a severely impaired Nfasc155-CNTN1/CASPR1 complex interaction as a result of the identified variants. Immunofluorescence staining of myelinated fibres from two affected individuals showed a severe loss of myelinated fibres and abnormalities in the paranodal junction morphology. Our results establish that recessive variants affecting the Nfasc155 isoform can affect the formation of paranodal axoglial junctions at the nodes of Ranvier. The genetic disease caused by biallelic NFASC variants includes neurodevelopmental impairment and a spectrum of central and peripheral demyelination as part of its core clinical phenotype. Our findings support possible overlapping molecular mechanisms of paranodal damage at peripheral nerves in both the immune-mediated and the genetic disease, but the observation of prominent central neurological involvement in NFASC biallelic variant carriers highlights the importance of this gene in human brain development and function

Expanding the genetic heterogeneity of intellectual disability

Intellectual disability (ID) is a common morbid condition with a wide range of etiologies. The list of monogenic forms of ID has increased rapidly in recent years thanks to the implementation of genomic sequencing techniques. In this study, we describe the phenotypic and genetic findings of 68 families (105 patients) all with novel ID-related variants. In addition to established ID genes, including ones for which we describe unusual mutational mechanism, some of these variants represent the first confirmatory disease-gene links following previous reports (TRAK1, GTF3C3, SPTBN4 and NKX6-2), some of which were based on single families. Furthermore, we describe novel variants in 14 genes that we propose as novel candidates (ANKHD1, ASTN2, ATP13A1, FMO4, MADD, MFSD11, NCKAP1, NFASC, PCDHGA10, PPP1R21, SLC12A2, SLK, STK32C and ZFAT). We highlight MADD and PCDHGA10 as particularly compelling candidates in which we identified biallelic likely deleterious variants in two independent ID families each. We also highlight NCKAP1 as another compelling candidate in a large family with autosomal dominant mild intellectual disability that fully segregates with a heterozygous truncating variant. The candidacy of NCKAP1 is further supported by its biological function, and our demonstration of relevant expression in human brain. Our study expands the locus and allelic heterogeneity of ID and demonstrates the power of positional mapping to reveal unusual mutational mechanisms

Outcome of Outpatient Autologous Hematopoietic Stem Cell Transplantation in Patients with Multiple Myeloma and Relapsed and Refractory Hodgkin Lymphoma. The Experience of King Fahad Specialist Hospital in Dammam, Saudi Arabia

Background: Autologous hematopoietic stem cell transplants (HSCT) is the standard of care for transplant-eligible patients with newly diagnosed multiple myeloma (MM) and patients with relapsed and refractory Hodgkin lymphoma (R/R-HL) who achieve chemosensitivity after salvage therapy. Although autologous HSCT is routinely performed in an  inpatient setting, the procedure can safely be performed in an  outpatient setting.Methods and materials: A retrospective study of patients with MM and R/R- HL who received outpatient autologous HSCT at King Fahad Specialist Hospital (KFSH) in Dammam, Saudi Arabia between the first of April 2017 and the 31st of January 2022 was performed.Results: Over the study period of 4 years and 10 months, a total of 90 outpatient autologous HSCTs were performed for 79 patients (54 patients with MM; 4 of them received planned tandem autografts and 7 other myeloma patients received second autologous HSCTs for relapsed or progressive disease; and 25 patients with R/R-HL) at our institution. The median ages of patients with MM and those with R/R-HL at HSCT were 50.4 years and 27.8 years respectively.At the presentation of their MM, the following high-risk (HR) features were encountered: stage II and III diseases according to the revised international scoring system (RISS) in 53.7%; adverse cytogenetics in 42.6% and extensive bone involvement in 53.7% of patients. In patients with HL at presentation, 48% of patients had stage IV disease according to Ann Arbor staging classification and 84% of patients had B symptoms.Survival for 100 days post-HSCT for all patients with MM and HL who received outpatient autologous transplants was 100%. For patients with MM, the overall survival (OS) rates at 3 years and 4 years post-HSCT were 80% and 67%, while the progression-free survival (PFS) rates over 3 years and 4 years were 58% and 38% respectively. For patients with HL, the OS at 6 years post-HSCT was 95% while the PFS rates at 3 years and 6 years post-HSCT were 84% and 62% respectively.Conclusion: Outpatient autologous HSCT for patients with MM and HL is safe, and feasible and can lead to short-term as well as long-term outcomes that are comparable to autologous transplantation performed in an  inpatient setting. Additional benefits of outpatient autologous include saving beds and reducing hospital costs

The outcome of autologous hematopoietic stem cell transplantation in patients with multiple myeloma. The experience of King Fahad Specialist Hospital in Dammam, Saudi Arabia

Background: Aautologous hematopoietic stem cell transplants (HSCT) is the standard of care for newly diagnosed patients with multiple myeloma (MM) who are eligible for autologous transplantation. Although cryopreservation is routinely employed, autologous HSCT can be performed using non-cryopreserved stem cells.Methods and materials: A retrospective study of patients with MM who received autologous HSCT between the 10th of October 2010 and the 31st of January 2022 at King Fahad Specialist Hospital (KFSH) in Dammam, Saudi Arabia was performed.Results: Over 11 years and 113 days, a total of 135 autologous HSCTs were performed for 119 patients with MM at our institution. Single autologous HSCTs were performed for 119 patients, while 16 of these patients received either planned tandem autologous transplants or second autografts due to either progression or relapse of their myeloma. The median age of patients with MM at autologous HSCT was 51.5 years. At presentation of their MM, the following high-risk (HR) features were encountered: stage III disease according to the revised international scoring system (RISS) in 12.3%; adverse cytogenetics in 31.93% of patients; advanced bone disease in 60.50%; and renal dysfunction or failure in 11.76% of patients. A total of 104 autologous HSCTs (77.04%) were performed without cryopreservation while 31 autografts (22.96%) were performed using cryopreserved apheresis stem cell products. Additionally, 54 autologous HSCTs (40.00%) were done at outpatient while 81 autografts (60.00%) were performed in an inpatient setting. Survival for 100 days post-HSCT for all patients with MM who received autologous transplants including those done at outpatient was 100%. The 4 years overall survival (OS) an progression-free survival (PFS) for patients with MM who received non- cryopreserved or fresh autologous HSCTs were 82% and 68% respectively.Conclusion: Autologous HSCT without cryopreservation is safe, and feasible and can lead to short-term as well as long-term outcomes that are comparable to autologous transplantation with cryopreservation. Non- cryopreserved autologous grafts allow the performance of autologous transplants in an outpatient setting to save beds and reduce costs

Metabolic and other morbid complications in congenital generalized lipodystrophy type 4

\ua9 2024 Wiley Periodicals LLC.Morbidity and mortality rates in patients with autosomal recessive, congenital generalized lipodystrophy type 4 (CGL4), an ultra-rare disorder, remain unclear. We report on 30 females and 16 males from 10 countries with biallelic null variants in CAVIN1 gene (mean age, 12 years; range, 2 months to 41 years). Hypertriglyceridemia was seen in 79% (34/43), hepatic steatosis in 82% (27/33) but diabetes mellitus in only 21% (8/44). Myopathy with elevated serum creatine kinase levels (346–3325 IU/L) affected all of them (38/38). 39% had scoliosis (10/26) and 57% had atlantoaxial instability (8/14). Cardiac arrhythmias were detected in 57% (20/35) and 46% had ventricular tachycardia (16/35). Congenital pyloric stenosis was diagnosed in 39% (18/46), 9 had esophageal dysmotility and 19 had intestinal dysmotility. Four patients suffered from intestinal perforations. Seven patients died at mean age of 17 years (range: 2 months to 39 years). The cause of death in four patients was cardiac arrhythmia and sudden death, while others died of prematurity, gastrointestinal perforation, and infected foot ulcers leading to sepsis. Our study highlights high prevalence of myopathy, metabolic abnormalities, cardiac, and gastrointestinal problems in patients with CGL4. CGL4 patients are at high risk of early death mainly caused by cardiac arrhythmias

Biallelic mutations in neurofascin cause neurodevelopmental impairment and peripheral demyelination

Axon pathfinding and synapse formation are essential processes for nervous system development and function. The assembly of myelinated fibres and nodes of Ranvier is mediated by a number of cell adhesion molecules of the immunoglobulin superfamily including neurofascin, encoded by the NFASC gene, and its alternative isoforms Nfasc186 and Nfasc140 (located in the axonal membrane at the node of Ranvier) and Nfasc155 (a glial component of the paranodal axoglial junction). We identified 10 individuals from six unrelated families, exhibiting a neurodevelopmental disorder characterized with a spectrum of central (intellectual disability, developmental delay, motor impairment, speech difficulties) and peripheral (early onset demyelinating neuropathy) neurological involvement, who were found by exome or genome sequencing to carry one frameshift and four different homozygous non-synonymous variants in NFASC. Expression studies using immunostaining-based techniques identified absent expression of the Nfasc155 isoform as a consequence of the frameshift variant and a significant reduction of expression was also observed in association with two non-synonymous variants affecting the fibronectin type III domain. Cell aggregation studies revealed a severely impaired Nfasc155-CNTN1/CASPR1 complex interaction as a result of the identified variants. Immunofluorescence staining of myelinated fibres from two affected individuals showed a severe loss of myelinated fibres and abnormalities in the paranodal junction morphology. Our results establish that recessive variants affecting the Nfasc155 isoform can affect the formation of paranodal axoglial junctions at the nodes of Ranvier. The genetic disease caused by biallelic NFASC variants includes neurodevelopmental impairment and a spectrum of central and peripheral demyelination as part of its core clinical phenotype. Our findings support possible overlapping molecular mechanisms of paranodal damage at peripheral nerves in both the immune-mediated and the genetic disease, but the observation of prominent central neurological involvement in NFASC biallelic variant carriers highlights the importance of this gene in human brain development and function