Phenotypic and genotypic analysis of limb-Girdle muscular dystrophy type 2B.

Dysferlinopathies are rare autosomal recessive muscular dystrophies caused by mutation in the dysferlin (DYSF) gene, resulting in varied phenotype. In this case report, we review a 26-year-old diabetic male patient who presented to hospital suffering from progressive muscle weakness. We confirmed the diagnosis of dysferlinopathy with phenotype of limb girdle muscular dystrophy, followed by a muscle biopsy, immunohistochemistry and a molecular technique, exome sequencing. The specific homozygous mutations in DYSF and heterozygous mutation PSAP genes identified in the present case of LGMD-2B are found in the Saudi population.

Corrigendum: Autozygosity reveals recessive mutations and novel mechanisms in dominant genes: implications in variant interpretation.

This corrects the article DOI: 10.1038/gim.2017.22.

The histological spectrum of tubulo-reticular inclusion positive renal biopsies: a tertiary hospital experience and review of the literature.

AIM: To identify the underlying diseases with TRI-positive kidney biopsies, and describe the histological pattern and spectrum of TRI-positive kidney biopsies. METHODS: A retrospective analysis of all patients' chart that underwent renal biopsy at King Saud University Medical City between 2012 and 2017 was done. Kidney biopsies that indicated a positive result for tubuloreticular inclusions (TRI's) on electron microscopy were reviewed and the underlying disease and histological pattern was extracted. RESULTS: Of 1,473 native kidney biopsies reviewed, 96 (6.5%) were TRI-positive. Of the 96 TRI-positive kidney biopsies, 87 (90.6%) were TRI-positive lupus nephritis (LN); of which 10 (11.5%) were Class V, 49 (56.3%) were active LN, and 28 (32.2%) were inactive LN. The underlying diseases of the nine non-LN TRI-positive cases included diabetic nephropathy, connective tissue disorders, immune complex mediated Glomerulonephritis (GN), acute thrombotic microangiopathy, rhabdomyolysis, and Wegener's disease. CONCLUSION: LN is a very common finding in TRI-positive kidney biopsies. Active LN and chronic LN are the more common classes of TRI-positive LN kidney biopsies, than pure membranous (Class V) LN. TRI positive kidney biopsies without LN are commonly found in diabetic nephropathy, connective tissue disorders and immune mediated GN's. This study highlights this finding in our patients cohort in opposition to what has been reported in the literature.

Brainstem encephalitis. A diagnostic dilemma.

Brainstem encephalitis (BE) is a rare, severe, and potentially life-threatening inflammation of the central nervous system. Brainstem encephalitis has multiple etiologies, which vary in treatment and outcomes. The current literature is generally focused on the infectious causes of BE, while little is known about the other entities, including cases with inconclusive diagnoses. Additionally, the outcomes of BE are not well documented. We present a case of an 18-year-old male who presented with progressive symptoms of brainstem involvement. His clinical investigations, including cerebrospinal fluid (CSF) analysis, were normal; magnetic resonance imaging (MRI) of the brain showed an enhancing medullary lesion, while tissue biopsy yielded no specific diagnosis. Multiple empirical treatments to address possible autoimmune and infectious processes were started with no significant improvement. He continued to deteriorate over a period of 12 weeks. Thereafter, following intensive supportive and rehabilitative care, he started to show slow signs of improvement.

Autozygosity reveals recessive mutations and novel mechanisms in dominant genes: implications in variant interpretation.

PURPOSE: The purpose of this study is to describe recessive alleles in strictly dominant genes. Identifying recessive mutations in genes for which only dominant disease or risk alleles have been reported can expand our understanding of the medical relevance of these genes both phenotypically and mechanistically. The Saudi population is enriched for autozygosity, which enhances the homozygous occurrence of alleles, including pathogenic alleles in genes that have been associated only with a dominant inheritance pattern. METHODS: Exome sequencing of patients from consanguineous families with likely recessive phenotypes was performed. In one family, the genotype of the deceased children was inferred from their parents due to lack of available samples. RESULTS: We describe the identification of 11 recessive variants (5 of which are reported here for the first time) in 11 genes for which only dominant disease or risk alleles have been reported. The observed phenotypes for these recessive variants were novel (e.g., FBN2-related myopathy and CSF1R-related brain malformation and osteopetrosis), typical (e.g., ACTG2-related visceral myopathy), or an apparently healthy state (e.g., PDE11A), consistent with the corresponding mouse knockout phenotypes. CONCLUSION: Our results show that, in the era of genomic sequencing and "reverse phenotyping," recessive variants in dominant genes should not be dismissed based on perceived "incompatibility" with the patient's phenotype before careful consideration.Genet Med advance online publication 06 April 2017.

Mutation of the mitochondrial carrier SLC25A42 causes a novel form of mitochondrial myopathy in humans.

Myopathies are heterogeneous disorders characterized clinically by weakness and hypotonia, usually in the absence of gross dystrophic changes. Mitochondrial dysfunction is a frequent cause of myopathy. We report a simplex case born to consanguineous parents who presented with muscle weakness, lactic acidosis, and muscle changes suggestive of mitochondrial dysfunction. Combined autozygome and exome analysis revealed a missense variant in the SLC25A42 gene, which encodes an inner mitochondrial membrane protein that imports coenzyme A into the mitochondrial matrix. Zebrafish slc25a42 knockdown morphants display severe muscle disorganization and weakness. Importantly, these features are rescued by normal human SLC25A42 RNA, but not by RNA harboring the patient's variant. Our data support a potentially causal link between SLC25A42 mutation and mitochondrial myopathy in humans.

A novel syndrome of Klippel-Feil anomaly, myopathy, and characteristic facies is linked to a null mutation in MYO18B.

BACKGROUND: Klippel-Feil anomaly (KFA) can be seen in a number of syndromes. We describe an apparently novel syndromic association with KFA. METHODS: Clinical phenotyping of two consanguineous families followed by combined autozygome/exome analysis. RESULTS: Two patients from two apparently unrelated families shared a strikingly similar phenotype characterised by KFA, myopathy, mild short stature, microcephaly, and distinctive facies. They shared a single founder autozygous interval in which whole exome sequencing revealed a truncating mutation in MYO18B. There was virtually complete loss of the transcript in peripheral blood, indicative of nonsense-mediated decay. Electron microscopy of muscle confirms abnormal myosin filaments with accompanying myopathic changes. CONCLUSIONS: Deficiency of MYO18B is linked to a novel developmental disorder which combines KFA with myopathy. This suggests a widespread developmental role for this gene in humans, as observed for its murine ortholog.

A novel syndrome of hypohidrosis and intellectual disability is linked to COG6 deficiency.

BACKGROUND: Numerous syndromic forms of intellectual disability have been described including those with abnormal sweating pattern. PURPOSE: To describe the clinical and molecular analysis of a large multiplex consanguineous Saudi family with an unusual constellation of severe intellectual disability, hypohidrosis, abnormal teeth, and acquired microcephaly. METHODS: Clinical evaluation, autozygosity mapping, exome sequencing, and expression analysis. RESULTS: Autozygosity mapping revealed a single critical locus corresponding to chr13:39 338 062-40 857 430. Exome sequencing uncovered a deep intronic (NM_020751.2:c.1167-24A>G) variant in COG6 that largely replaces the consensus acceptor site, resulting in pronounced reduction of the normal transcript and consequent deficiency of COG6 protein. Patient cells also exhibited pronounced deficiency of STX6, consistent with the established stabilising effect of COG6 on STX6. Four additional patients representing two families of the same tribal origin as the original family were found to have the same mutation, confirming a founder effect. Remarkably, none of the patients displayed any detectable abnormality in the glycosylation pattern of transferrin, which contradicts a previously published report of a patient whose abnormal glycosylation pattern was presumed to be caused by a missense variant in COG6. CONCLUSIONS: Our data implicate COG6 in the pathogenesis of a novel hypohidrotic disorder in humans that is distinct from congenital disorders of glycosylation.

Microscopic and ultrastructural changes of Müller's muscle in patients with simple congenital ptosis.

PURPOSE: To study microscopic and ultrastructural changes of Müller's muscle in patients with isolated congenital ptosis. METHODS: In this prospective, observational case-control study, Müller's muscle specimens were collected during ptosis surgical correction for 18 consecutive patients. Each specimen was divided into 2 parts. One part was embedded in formalin for light microscopy, and the other one was fixed in 3% glutaraldehyde for electron microscopy. A neuropathologist, serving as a masked evaluator, blindly reviewed all the different features for every case and counted the number of myocytes showing distinct myofilaments in the whole grid for every case. Statistical analysis using compare means and correlation tests was conducted to investigate potential associations and/or differences within and across groups. RESULTS: Twelve Müller's muscle specimens from patients with simple congenital ptosis of various severities and 6 specimens from patients with aponeurotic ptosis (controls) were collected and studied. Under light microscopy, congenital ptosis slides showed a small number of dispersed myocytes in a fibrotic background, whereas acquired ptosis slides showed a greater number of well-defined myocytes. Under electron microscopy, all congenital ptosis specimens had only a very small number of myocytes with clear, distinct myofilaments. Most myocytes in the aponeurotic ptosis group showed clear, distinct myofilaments, indicating a well-preserved muscle. No relationship existed between the number of clear, distinct myofilaments observed in the congenital ptosis group by transmission electron microscopy and patient age or ptosis severity. CONCLUSION: Substantial Müller's muscle atrophy was observed in patients with different severities of isolated congenital ptosis.

A 55-Year-Old Woman Presenting with a Second Diagnosis of Craniopharyngioma Following Diagnosis and Successful Treatment of Craniopharyngioma as a 5-Year-Old Child.

BACKGROUND Craniopharyngioma is a rare, partly cystic embryonic malformation of the sellar and parasellar region and is usually benign. This report is of a 55-year-old woman presenting with a second diagnosis of craniopharyngioma following diagnosis and successful treatment of craniopharyngioma as a 5-year-old child. CASE REPORT Our patient was diagnosed with craniopharyngioma at age 5 when she presented with headaches accompanied by nausea and vomiting, decreased visual acuity, polyurea, and polydipsia for 6 months. She was found to have diplopia and grade II papilledema. A skull X-ray showed separation of the sutures and a calcified mass in the suprasellar region. A pneumoencephalogram showed extension of the tumor into the third ventricle. Surgery was performed via transcallosal approach followed by radiotherapy at 5000 rays. She was followed up clinically and radiologically and had been disease-free until age 55, when she presented with headache and facial numbness. On examination, she had right-eye Horner syndrome, decreased sensation in the right side of the face, diplopia, and grade 2 facial palsy. An MRI revealed interval significant recurrence of the craniopharyngioma at the sellar/suprasellar mass with extension to the right Meckel's cave and the right posterior fossa. On April 6, 2023, she underwent surgical resection through a right-sided craniotomy and Kawase approach. This was followed by CyberKnife radiation therapy. CONCLUSIONS This report has presented a rare recurrence of craniopharyngioma with a 50-year interval and has highlighted the challenges in the diagnosis and the multidisciplinary approach to patient diagnosis and management.

A New Sarcoma Shortly after Treatment for High-Grade Glioma with Adjuvant Chemoradiation: A Case Report.

Introduction: High-grade gliomas are central nervous system tumors conventionally treated with surgery followed by adjuvant chemoradiotherapy. Secondary cancer due to radiation therapy is a rare yet established phenomenon that typically occurs years after radiation therapy. Case Presentation: In this case, we discuss an early presentation of a second cancer adjacent to the radiation field. This case report is of a 52-year-old male who developed a new scalp sarcoma at the site of primary surgery 8 months after radiation therapy. Genetic testing revealed a heterozygous missense variant in the NF1 gene, a variant of uncertain significance. The report highlights that this case does not conform to the expected criteria for postradiation sarcoma in terms of timing. Conclusion: Secondary cancers may arise earlier than expected, even in phenotypically normal patients, as they may have unmanifested variants of relevant mutations. The question of pre-radiotherapy screening for radiosensitivity syndromes and diseases requires further study, as current data are limited and do not provide enough insight into the significance of different genetic variants.

Genomic analysis of mitochondrial diseases in a consanguineous population reveals novel candidate disease genes.

OBJECTIVE: To investigate the utility of autozygome analysis and exome sequencing in a cohort of patients with suspected or confirmed mitochondrial encephalomyopathy. METHODS: Autozygome was used to highlight candidate genes for direct sequencing in 10 probands, all born to consanguineous parents. Autozygome was also used to filter the variants from exome sequencing of four probands. RESULTS: In addition to revealing mutations in known mitochondrial genes, the analysis revealed the identification of two novel candidate disease genes: MFF and FARS2, encoding the mitochondrial fission factor and phenylalanyl-tRNA synthetase, respectively. INTERPRETATION: These findings expand the repertoire of genes that are mutated in patients with mitochondrial disorders and highlight the value of integrating genomic approaches in the evaluation of these patients.

Finger Flexor Weakness in Myasthenia Gravis.

Myasthenia gravis (MG) affects the ocular, bulbar, and proximal limb muscles. The involvement of distal limb muscles is uncommon. MG-related weakness that severely affects the finger flexors and spares finger extensors and intrinsic hand muscles have never been reported. Here, we report a 35-year-old woman with acetylcholine receptor-antibody positive generalised MG who presented with severe bilateral asymmetric (left worse than right) finger flexor weakness during an MG relapse. The remaining muscles including the median and ulnar intrinsic hand muscles were normal. Repetitive nerve stimulation test showed decremental responses of more than 10%. Magnetic resonance imaging showed short-T1 inversion recovery sequences and increased signal intensities in the volar forearm muscles. Needle electromyography revealed fibrillations and positive sharp waves, small amplitude, short-duration, and polyphasic early recruiting motor unit action potentials. Myositis-specific autoantibodies were negative. Muscle biopsy showed neurogenic features. The patient had a good recovery with immunotherapy. We conclude that clinicians should be aware that marked weakness of the finger flexors can occur as a result of an MG relapse and may require early aggressive therapy. Key Words: Electromyography, Finger flexors, Muscle, Biopsy, Myasthenia gravis.

Ten-year survival in glioblastoma patient with neurofibromatosis type 1: illustrative case.

BACKGROUND: Gliomas are commonly detected in patients with neurofibromatosis type 1 (NF1) at an early age. Few patients with NF1 are diagnosed with glioblastoma. The course of management, response to therapy, and prognosis of such patients are unknown. Few reports have shown longer-than-average survival rates for patients with NF1 with glioblastoma. OBSERVATIONS: A 27-year-old man with NF1 presented with symptoms of high intracranial pressure. Imaging and pathology showed left frontotemporal glioblastoma. Gross total resection was achieved, and concurrent chemoradiotherapy was administered. Recurrence of tumor was detected 48 months later, and the patient underwent tumor debulking and concurrent chemoradiotherapy. The patient received first-, second-, and third-line chemotherapy (temozolomide, bevacizumab, bevacizumab/irinotecan) with good tolerance and has survived >10 years since then with good functional status. LESSONS: This case demonstrates >10 years overall survival of glioblastoma in a patient with NF1. Reports of patients with NF1 with longer survival may be attributed to the young age at diagnosis and relatively better tolerance for therapy. It might also support the growing evidence of a unique subset of glioblastoma associated with NF1 and opens the door for a more molecular targeted therapy in the future.

Adenoid cystic carcinoma of the orbit with bilateral cavernous sinus extension: A case report.

INTRODUCTION AND IMPORTANCE: Adenoid cystic carcinoma (ACC) is an uncommon malignant epithelial tumor of the salivary and lacrimal glands. Orbital ACC is rare, originating commonly from the lacrimal gland, with only a few cases reported without lacrimal gland involvement. Deep orbital ACC may be associated with extension into skull base structures, and further intracranial invasion. CASE PRESENTATION: We report a 47-year-old gentleman who presented with insidious onset of bilateral proptosis, left ophthalmoplegia, and loss of vision. Imaging revealed left orbital infiltrative mass with intracranial invasion and bilateral cavernous sinus extension. The lacrimal gland was not involved clinically nor radiologically. Histopathology showed ACC with classical cribriform pattern. There was no evidence of primary source of tumor or metastasis. DISCUSSION: ACC of the orbit commonly originates from the lacrimal gland. Only a few cases of orbital ACC without lacrimal gland involvement were found in English literature. Workup for our patient did not reveal a primary source of tumor. Tumor may have risen from ectopic orbital lacrimal gland tissue, extension from non-orbital sites, or through perineural or hematogenous spread. Only one case of bilateral cavernous sinus extension has been previously reported. Treatment for advanced orbital ACC is exenteration in most cases. However, due to the advanced nature of disease in our patient, palliative radiotherapy was the treatment of choice. CONCLUSION: Orbital ACC of non-lacrimal origin is rare and is associated with high morbidity and mortality. Early recognition and treatment are key for preventing organ and life-threatening complications such as advanced intracranial spread.

Early onset of capsular contracture after breast augmentation with implant: report of two cases & review of literature.

Capsular contracture (CC) is a local complication caused by an inflammatory reaction that leads to fibrosis. CC commonly occurs after one year of surgery. Hence, there has been no previously reported early onset of CC. Therefore, we report two unusual cases of early onset of post-breast reconstruction capsular contracture.

Embryonal tumor with multilayered rosettes: a report of a rare case.

The authors report a case of an embryonal tumor with multilayered rosettes (ETMR) in an 18-month-old female infant who presented with gait imbalance and progressive left-sided weakness for 2 months. ETMR is a rare small round blue cell aggressive tumor of the central nervous system characterized by the amplification of the C19MC region on chromosome 19 (Chr19q13.42). This report in detail the clinical-radiologic and histopathological workup and diagnosis. Because ETMRs are newly described rare pediatric central nervous system tumors with only a few reported cases, we aim to document this typical case to add to the existing data on these tumors.

Genomic, Proteomic, and Phenotypic Spectrum of Novel O-Sialoglycoprotein Endopeptidase Variant in Four Affected Individuals With Galloway-Mowat Syndrome.

Galloway-Mowat syndrome is a rare autosomal recessive disease characterized by a unique combination of renal and neurological manifestations, including early-onset steroid-resistant nephrotic syndrome, microcephaly, psychomotor delay, and gyral abnormalities of the brain. Most patients die during early childhood. Here, we identified a novel homozygous O-sialoglycoprotein endopeptidase (OSGEP) variant, NM_017807.3:c.973C>G (p.Arg325Gly), in four affected individuals in an extended consanguineous family from Saudi Arabia. We have described the detailed clinical characterization, brain imaging results, and muscle biopsy findings. The described phenotype varied from embryonic lethality to early pregnancy loss or death at the age of 9. Renal disease is often the cause of death. Protein modeling of this OSGEP variant confirmed its pathogenicity. In addition, proteomic analysis of the affected patients proposed a link between the KEOPS complex function and human pathology and suggested potential pathogenic mechanisms.

Exome Sequencing Reveals Novel TTN Variants in Saudi Patients with Congenital Titinopathies.

Aim: Our goal was to determine the genetic basis of early-onset myopathy in patients from two unrelated families. Materials and Methods: Whole-exome sequencing, autozygosity mapping, and confirmatory targeted Sanger sequencing were performed using genomic DNA extracted from blood samples from three myopathic patients of two unrelated families. Variant filtering and pathogenicity analyses were evaluated according to standard protocols and up-to-date pipelines applied at the King Faisal Specialist Hospital and Research Center. Results: A novel homozygous variant was detected in TTN gene within the first three M-line-encoding exons in a 9-year-old female in the first family who had delayed motor development and proximal weakness. Her 4-year-old affected brother, with the same homozygous variant, could not yet walk without help. This pathogenic nonsense variant is predicted to cause a premature stop during translation. In the second family we identified two novel variants as compound heterozygosites (a deletion and a variant affecting a canonical splice site) in an affected 9-year-old female with weakness that developed at age 3, in the second family. SpliceAI predicted the variants being splice-altering with high probability. These variants were fully segregated in the family. The deletion was found to be on the paternal allele, whereas the splicing variant was on the maternal allele. The patient's echocardiography revealed mitral valve prolapse with mild mitral regurgitation. Muscle histology showed minicores that were also confirmed by electron microscopy. Conclusion: Our study identified novel pathogenic variants in the TTN gene that are likely responsible for the phenotype of early-onset myopathy; hence, expanding genotype-phenotype relationship of titinopathies.

Efficient identification of novel mutations in patients with limb girdle muscular dystrophy.

Limb girdle muscular dystrophy type 2 (LGMD2) is a genetically heterogeneous autosomal recessive disorder caused by mutations in 15 known genes. DNA sequencing of all candidate genes can be expensive and laborious, whereas a selective sequencing approach often fails to provide a molecular diagnosis. We aimed to efficiently identify pathogenic mutations via homozygosity mapping in a population in which the genetics of LGMD2 has not been well characterized. Thirteen consanguineous families containing a proband with LGMD2 were recruited from Saudi Arabia, and for 11 of these families, selected individuals were genotyped at 10,204 single nucleotide polymorphisms. Linkage analysis excluded all but one or two known genes in ten of 11 genotyped families, and haplotype comparisons between families allowed further reduction in the number of candidate genes that were screened. Mutations were identified by DNA sequencing in all 13 families, including five novel mutations in four genes, by sequencing at most two genes per family. One family was reclassified as having a different myopathy based on genetic and clinical data after linkage analysis excluded all known LGMD2 genes. LGMD2 subtypes A and B were notably absent from our sample of patients, indicating that the distribution of LGMD2 mutations in Saudi Arabian families may be different than in other populations. Our data demonstrate that homozygosity mapping in consanguineous pedigrees offers a more efficient means of discovering mutations that cause heterogeneous disorders than comprehensive sequencing of known candidate genes.