Novel phenotype associated with homozygous likely pathogenic variant in the POP1 gene.

The biallelic variants of the POP1 gene are associated with the anauxetic dysplasia (AAD OMIM 607095), a rare skeletal dysplasia, characterized by prenatal rhizomelic shortening of limbs and generalized joint hypermobility. Affected individuals usually have normal neurodevelopmental milestones. Here we present three cases from the same family with likely pathogenic homozygous POP1 variant and a completely novel phenotype: a girl with global developmental delay and autism, microcephaly, peculiar dysmorphic features and multiple congenital anomalies. Two subsequent pregnancies were terminated due to multiple congenital malformations. Fetal DNA samples revealed the same homozygous variant in the POP1 gene. Expression of the RMRP was reduced in the proband compared with control and slightly reduced in both heterozygous parents, carriers for this variant. To our knowledge, this is the first report of this new phenotype, associated with a novel likely pathogenic variant in POP1. Our findings expand the phenotypic spectrum of POP1-related disorders.

Expanding the natural history of CASK-related disorders to the prenatal period.

AIM: To assess whether microcephaly with pontine and cerebellar hypoplasia (MICPCH) could manifest in the prenatal period in patients with calcium/calmodulin-dependent serine protein kinase (CASK) gene disorders. METHOD: In this international multicentre retrospective study, we contacted a CASK parents' social media group and colleagues with expertise in cerebellar malformations and asked them to supply clinical and imaging information. Centiles and standard deviations (SD) were calculated according to age by nomograms. RESULTS: The study consisted of 49 patients (44 females and 5 males). Information regarding prenatal head circumference was available in 19 patients; 11 out of 19 had a fetal head circumference below -2SD (range -4.1SD to -2.02SD, mean gestational age at diagnosis 20 weeks). Progressive prenatal deceleration of head circumference growth rate was observed in 15 out of 19. At birth, 20 out of 42 had a head circumference below -2SD. A total of 6 out of 15 fetuses had a TCD z-score below -2 (range -5.88 to -2.02). INTERPRETATION: This study expands the natural history of CASK-related disorders to the prenatal period, showing evidence of progressive deceleration of head circumference growth rate, head circumference below -2SD, or small TCD. Most cases will not be diagnosed according to current recommendations for fetal central nervous system routine assessment. Consecutive measurements and genetic studies are advised in the presence of progressive deceleration of head circumference growth rates or small TCD. WHAT THIS PAPER ADDS: Progressive deceleration of fetal head circumference growth rate can be observed. A small transcerebellar diameter is an additional important manifestation. Most cases will not be diagnosed according to current recommendations for fetal central nervous system routine assessment. Consecutive measurements are advised when measurements are within the low range of norm.

Juvenile mucopolysaccharidosis plus disease caused by a missense mutation in VPS33A.

A rare and fatal disease resembling mucopolysaccharidosis in infants, is caused by impaired intracellular endocytic trafficking due to deficiency of core components of the intracellular membrane-tethering protein complexes, HOPS, and CORVET. Whole exome sequencing identified a novel VPS33A mutation in a patient suffering from a variant form of mucopolysaccharidosis. Electron and confocal microscopy, immunoblotting, and glycosphingolipid trafficking experiments were undertaken to investigate the effects of the mutant VPS33A in patient-derived skin fibroblasts. We describe an attenuated juvenile form of VPS33A-related syndrome-mucopolysaccharidosis plus in a man who is homozygous for a hitherto unknown missense mutation (NM_022916.4: c.599 G>C; NP_075067.2:p. Arg200Pro) in a conserved region of the VPS33A gene. Urinary glycosaminoglycan (GAG) analysis revealed increased heparan, dermatan sulphates, and hyaluronic acid. We showed decreased abundance of VPS33A in patient derived fibroblasts and provided evidence that the p.Arg200Pro mutation leads to destablization of the protein and proteasomal degradation. As in the infantile form of mucopolysaccharidosis plus, the endocytic compartment in the fibroblasts also expanded-a phenomenon accompanied by increased endolysosomal acidification and impaired intracellular glycosphingolipid trafficking. Experimental treatment of the patient's cultured fibroblasts with the proteasome inhibitor, bortezomib, or exposure to an inhibitor of glucosylceramide synthesis, eliglustat, improved glycosphingolipid trafficking. To our knowledge this is the first report of an attenuated juvenile form of VPS33A insufficiency characterized by appreciable residual endosomal-lysosomal trafficking and a milder mucopolysaccharidosis plus than the disease in infants. Our findings expand the proof of concept of redeploying clinically approved drugs for therapeutic exploitation in patients with juvenile as well as infantile forms of mucopolysaccharidosis plus disease.

Major brain malformations: corpus callosum dysgenesis, agenesis of septum pellucidum and polymicrogyria in patients with BCORL1-related disorders.

OBJECTIVE: BCORL1, a transcriptional co-repressor, has a role in cortical migration, neuronal differentiation, maturation, and cerebellar development. We describe BCORL1 as a new genetic cause for major brain malformations. METHODS AND RESULTS: We report three patients from two unrelated families with neonatal onset intractable epilepsy and profound global developmental delay. Brain MRI of two siblings from the first family depicted hypoplastic corpus callosum and septal agenesis (ASP) in the older brother and unilateral perisylvian polymicrogyria (PMG) in the younger one. MRI of the patient from the second family demonstrated complete agenesis of corpus callosum (CC). Whole Exome Sequencing revealed a novel hemizygous variant in NM_021946.5 (BCORL1):c.796C>T (p.Pro266Ser) in the two siblings from the first family and the NM_021946.5 (BCORL1): c.3376G>A; p.Asp1126Asn variant in the patient from the second family, both variants inherited from healthy mothers. We reviewed the patients' charts and MRIs and compared the phenotype to the other published BCORL1-related cases. Brain malformations have not been previously described in association with the BCORL1 phenotype. We discuss the potential influence of BCORL1 on brain development. CONCLUSIONS: We suggest that BCORL1 variants present with a spectrum of neurodevelopmental disorders and can lead to major brain malformations originating at different stages of fetal development. We suggest adding BCORL1 to the genetic causes of PMG, ASP, and CC dysgenesis.

Expanding the genotype-phenotype spectrum of ISCA2-related multiple mitochondrial dysfunction syndrome-cavitating leukoencephalopathy and prolonged survival.

Iron-sulfur cluster assembly 2 (ISCA2)-related multiple mitochondrial dysfunction syndrome 4 (MMDS4) is a fatal autosomal recessive mitochondrial leukoencephalopathy. The disease typically manifests with rapid neurodevelopmental deterioration during the first months of life leading to a vegetative state and early death. MRI demonstrates a demyelinating leukodystrophy. We describe an eleven-year-old boy with a milder phenotype of ISCA2 related disorder manifesting as: normal early development, acute infantile neurologic deterioration leading to stable spastic quadriparesis, optic atrophy and mild cognitive impairment. The first MRI demonstrated a diffuse demyelinating leukodystrophy. A sequential MRI revealed white matter rarefaction with well-delineated cysts. The patient harbors two novel bi-allelic variants (p.Ala2Asp and p.Pro138Arg) in ISCA2 inherited from heterozygous carrier parents. This report expands the clinical spectrum of ISCA2-related disorders to include a milder phenotype with a longer life span and better psychomotor function and cavitating leukodystrophy on MRI. We discuss the possible genetic explanation for the different presentation.

Brain white matter abnormalities associated with copy number variants.

White matter (WM) signal abnormalities are demonstrated in various neurodevelopmental disorders on brain magnetic resonance imaging (MRI). The pattern of WM abnormalities can aid in the diagnostic process. This study aims to characterize the WM changes found in microdeletion/microduplication syndromes. Thirteen patients with neurodevelopmental disorders due to copy number variations were collected from a cohort of children with evidence of WM abnormalities on brain MRI, in two medical centers. A pediatric neuroradiologist blindly interpreted the MRI scans. Clinical and genetic findings were retrospectively extracted from the medical records. WM changes included: multifocal (10/13) periventricular (12/13) and subcortical (5/13) signal abnormalities and WM volume loss (6/13). Dysgenesis of the corpus callosum was depicted in 12/13. The main clinical features were: global developmental delay (13/13), hypotonia (11/13), epilepsy (10/13), dysmorphic features (9/13), microcephaly (6/13), short stature (6/13), and systemic involvement (6/13). We showed that different chromosomal micro-rearrangement syndromes share similar MRI patterns of nonspecific multifocal predominantly periventricular WM changes associated with corpus callosum dysgenesis with or without WM and gray matter loss. Hence, the association of these features in a patient evaluated for global developmental delay/intellectual disability suggests a chromosomal micro-rearrangement syndrome, and a chromosomal microarray analysis should be performed.

Bilateral polymicrogyria associated with dystonia: A new neurogenetic syndrome?

The clinical presentation of bilateral perisylvian polymicrogyria (PMG) is highly variable, including oromotor dysfunction, epilepsy, intellectual disability, and pyramidal signs. Extrapyramidal features are extremely rare. We present four apparently unrelated patients with a unique association of PMG with dystonia. The clinical, genetic, and radiologic features are described and possible mechanisms of dystonia are discussed. All patients were female and two were born to consanguineous families. All presented with early childhood onset dystonia. Other neurologic symptoms and signs classically seen in bilateral perisylvian PMG were observed, including oromotor dysfunction and speech abnormalities ranging from dysarthria to anarthria (4/4), pyramidal signs (3/4), hypotonia (3/4), postnatal microcephaly (1/4), and seizures (1/4). Neuroimaging showed a unique pattern of bilateral PMG with an infolded cortex originating primarily from the perisylvian region in three out of four patients. Whole exome sequencing was performed in two out of four patients and did not reveal pathogenic variants in known genes for cortical malformations or movement disorders. The dystonia seen in our patients is not described in bilateral PMG and suggests an underlying mechanism of impaired connectivity within the motor network or compromised cortical inhibition. The association of bilateral PMG with dystonia in our patients may represent a new neurogenetic disorder.

Prenatal and postnatal presentation of PRMT7 related syndrome: Expanding the phenotypic manifestations.

Protein arginine methyltransferase 7 (PRMT7) is a member of a family of enzymes that catalyze the transfer of methyl groups from S-adenosyl-l-methionine to nitrogen atoms on arginine residues. Arginine methylation is involved in multiple biological processes, such as signal transduction, mRNA splicing, transcriptional control, DNA repair, and protein translocation. Currently, 10 patients have been described with mutations in PRMT7. The shared findings include: hypotonia, intellectual disability, short stature, brachydactyly, and mild dysmorphic features. We describe the prenatal, postnatal, and pathological findings in two male sibs homozygote for a mutation in PRMT7. Both had intrauterine growth restriction involving mainly the long bones. In addition, eye tumor was found in the first patient, and nonspecific brain calcifications and a systemic venous anomaly in the second. The pregnancy of the first child was terminated and we describe the autopsy findings. The second child had postnatal growth restriction of prenatal onset, hypotonia, strabismus, sensorineural hearing loss, genitourinary and skeletal involvement, and global developmental delay. He had dysmorphic features that included frontal bossing, upslanting palpebral fissures, small nose with depressed nasal bridge, and pectus excavatum. Our patients provide additional clinical and pathological data and expand the phenotypic manifestations associated with PRMT7 homozygote/compound heterozygote mutations to include brain calcifications and delayed myelination, and congenital orbital tumor.

Metabolic stroke in a patient with bi-allelic OPA1 mutations.

OPA1 related disorders include: classic autosomal dominant optic atrophy syndrome (ADOA), ADOA plus syndrome and a bi-allelic OPA1 complex neurological disorder. We describe metabolic stroke in a patient with bi-allelic OPA1 mutations. A twelve-year old girl presented with a complex neurological disorder that includes: early onset optic atrophy at one year of age, progressive gait ataxia, dysarthria, tremor and learning impairment. A metabolic stroke occurred at the age of 12 years. The patient was found to harbor a de novo heterozygous frame shift mutation c.1963_1964dupAT; p.Lys656fs (NM_015560.2) and a missense mutation c.1146A > G; Ile382Met (NM_015560.2) inherited from her mother. The mother, aunt, and grandmother are heterozygous for the Ile382Met mutation and are asymptomatic. The co-occurrence of bi-allelic mutations can explain the severity and the early onset of her disease. This case adds to a growing number of patients recently discovered with bi-allelic OPA1 mutations presenting with a complex and early onset neurological disorder resembling Behr syndrome. To the best of our knowledge metabolic stroke has not been described before as an OPA1 related manifestation. It is important to be aware of this clinical feature for a prompt diagnosis and consideration of available treatment.

Multiple Causes of Pediatric Early Onset Chorea-Clinical and Genetic Approach.

OBJECTIVE: This article elucidates a clinical and genetic approach to pediatric early-onset chorea in patients with normal neuroimaging. METHODS: We retrospectively studied patients with onset hyperkinetic movement disorders. Only children with onset of chorea in the first 3 years of life were included, those with an abnormal magnetic resonance imaging (MRI) or electroencephalogram (EEG) were excluded.We studied the movement disorder phenotype by clinical examination and by interpretation of videos and compared our data to the literature. RESULTS: Four patients, aged 2 to 13 years, were diagnosed. Abnormal involuntary movements appeared between the ages of 6 months to 3 years in association with developmental delay. One patient has a close relative with NKX2.1-related chorea. One patient is from Iraqi-Jewish origin. Facial twitches and nocturnal dyskinetic attacks were observed in one.The unique clinical presentation and family history enabled genetic diagnosis by molecular analysis of a specific mutation in two (NKX2.1, OPA3) and Sanger sequencing of a target gene in one (ADCY5). One patient was diagnosed by whole-exome sequencing (WES) (GNAO1). CONCLUSION: By carefully recording the phenotype and genetic background, a single gene can be suspected in some cases. In the rest, we suggest multigene panels or WES study.

Severe growth deficiency, microcephaly, intellectual disability, and characteristic facial features are due to a homozygous QARS mutation.

Glutaminyl tRNA synthase is highly expressed in the developing fetal human brain. Mutations in the glutaminyl-tRNA synthetase (QARS) gene have been reported in patients with progressive microcephaly, cerebral-cerebellar atrophy, and intractable seizures. We have previously reported a new recessive syndrome of severe linear growth retardation, poor weight gain, microcephaly, characteristic facial features, cutaneous syndactyly of the toes, high myopia, and intellectual disability in two sisters of Ashkenazi-Jewish origin (Eur J Med Genet 2014;57(6):288-92). Homozygosity mapping and whole exome sequencing revealed a homozygous missense (V476I) mutation in the QARS gene, located in the catalytic domain. The patient's fibroblasts demonstrated markedly reduced QARS amino acylation activity in vitro. Furthermore, the same homozygous mutation was found in an unrelated girl of Ashkenazi origin with the same phenotype. The clinical presentation of our patients differs from the original QARS-associated syndrome in the severe postnatal growth failure, absence of epilepsy, and minor MRI findings, thus further expanding the phenotypic spectrum of the glutaminyl-tRNA synthetase deficiency syndromes.

Riboflavin-responsive lipid-storage myopathy in elderly patients.

There are scarce reports of riboflavin-responsive lipid storage myopathy in elderly patients with onset in their sixties. We describe three elderly patients with riboflavin-responsive lipid-storage myopathy. All three patients (aged 67-71 years on first examination) had subacute onset of neck extensors and proximal limb weakness progressing to inability to rise from a sitting position or to walk. Muscle biopsies showed vacuoles with lipid content, mainly in type 1 fibers. Genetic analysis failed to identify any pathogenic variant in one patient, identified a heterozygous variant of uncertain significance c.812 A > G; p.Tyr271Cys in the ETFDH gene in the second patient, and revealed a heterozygote likely pathogenic variant c.1286-2 A > C in the ETFDH gene predicted to cause abnormal splicing in the third patient. All patients responded to treatment with riboflavin and carnitine, and regained normal strength. This report emphasizes the importance of muscle biopsy in revealing treatable lipid storage myopathy in elderly patients with progressive myopathy of unidentifiable cause.

Utility of genetic testing in children with leukodystrophy.

BACKGROUND: Leukodystrophies are monogenic disorders primarily affecting the white matter. We aimed to evaluate the utility of genetic testing and time-to-diagnosis in a retrospective cohort of children with suspected leukodystrophy. METHODS: Medical records of patients who attended the leukodystrophy clinic at the Dana-Dwek Children's Hospital between June 2019 and December 2021 were retrieved. Clinical, molecular, and neuroimaging data were reviewed, and the diagnostic yield was compared across genetic tests. RESULTS: Sixty-seven patients (Female/Male ratio 35/32) were included. Median age at symptom onset was 9 months (interquartile range (IQR) 3-18 months), and median length of follow-up was 4.75 years (IQR 3-8.5). Time from symptom onset to a confirmed genetic diagnosis was 15months (IQR 11-30). Pathogenic variants were identified in 60/67 (89.6%) patients; classic leukodystrophy (55/67, 82.1%), leukodystrophy mimics (5/67, 7.5%). Seven patients (10.4%) remained undiagnosed. Exome sequencing showed the highest diagnostic yield (34/41, 82.9%), followed by single-gene sequencing (13/24, 54%), targeted panels (3/9, 33.3%) and chromosomal microarray (2/25, 8%). Familial pathogenic variant testing confirmed the diagnosis in 7/7 patients. A comparison between patients who presented before (n = 31) and after (n = 21) next-generation sequencing (NGS) became clinically available in Israel revealed that the time-to-diagnosis was shorter in the latter group with a median of 12months (IQR 3.5-18.5) vs. a median of 19 months (IQR 13-51) (p = 0.005). CONCLUSIONS: NGS carries the highest diagnostic yield in children with suspected leukodystrophy. Access to advanced sequencing technologies accelerates speed to diagnosis, which is increasingly crucial as targeted treatments become available.

Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds.

BACKGROUND: Pseudomonas aeruginosa adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA) and PA-IIL (LecB). The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant P. aeruginosa infections in immunodeficient and cystic fibrosis (CF) patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen Chromobacterium violaceum) are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys. METHODS: The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins. RESULTS: The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low (< 10 KDa) and high MW (> 10 kDa) compounds (including glycoproteins) in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly. CONCLUSIONS: Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections.

Preventing Ralstonia solanacearum adhesion with glycans from cashew, cocoa, coffee, pumpkin, and tomato seed extract.

Ralstonia solanacearum wilts many plants, causing heavy agricultural losses. Its pathogenic strain ATCC 11696 produces 2 hemagglutinating lectins: RSL and RS-IIL. These lectins may bind to terminal l-fucose-, d-arabinose-, and d-mannose-bearing seedling xylem cell wall glycans, thus enabling pathogen adhesion to them, with devastating infection establishment. Blocking the active sites of these lectins with seed embryo-surrounding oligo- and poly-saccharides hampers binding of the lectins to the embryos. The current study shows that seeds of cashew, cocoa, coffee, pumpkin, and tomato contain low and high molecular mass glycans that block RSL and RS-IIL (like its homologous Pseudomonas aeruginosa PA-IIL lectin). The blocking of the pathogen lectins, which is attributable to the documented composition of the oligo- and poly-saccharides of these seeds, is similar to that observed with animal glycoproteins of avian egg whites (protecting their embryos from infections) and of milk and royal jelly, which likewise protect mammal and bee neonates, respectively. RSL was most strongly inhibited by cashew seed glycans, and RS-IIL by coffee seed glycans. Western blot analyses with these lectins instead of antibodies revealed the hitherto undescribed presence of lectin-binding glycoproteins in the coffee, pumpkin, tomato, and cashew (but not cocoa) seeds. The use of these lectins for unveiling potent embryo-protecting seed glycans might be helpful for seedling-bioprotection projects similar to those planned for animal protection against antibiotic-resistant infections.

Glycogen Debrancher Enzyme Deficiency Myopathy.

ABSTRACT: Glycogen storage disease type III is a rare inherited disease caused by decreased activity of glycogen debranching enzyme. It affects primarily the liver, cardiac muscle, and skeletal muscle. Pure involvement of the skeletal muscle with adult onset is extremely rare. We report on a patient with myopathy due to glycogen storage disease III, and describe the clinical features, and pathologic and genetic findings.

Congenital Mirror Movements Associated With Brain Malformations.

BACKGROUND: Congenital mirror movements are involuntary movements of a side of the body imitating intentional movements on the opposite side, appearing in early childhood and persisting beyond 7 years of age. Congenital mirror movements are usually idiopathic but have been reported in association with various brain malformations. METHODS: We describe clinical, genetic, and radiologic features in 9 individuals from 5 families manifesting congenital mirror movements. RESULTS: The brain malformations associated with congenital mirror movements were: dysplastic corpus callosum in father and daughter with a heterozygous p.Met1* mutation in DCC; hypoplastic corpus callosum, dysgyria, and malformed vermis in a mother and son with a heterozygous p.Thr312Met mutation in TUBB3; dysplastic corpus callosum, dysgyria, abnormal vermis, and asymmetric ventricles in a father and 2 daughters with a heterozygous p.Arg121Trp mutation in TUBB; hypoplastic corpus callosum, dysgyria, malformed basal ganglia and abnormal vermis in a patient with a heterozygous p.Glu155Asp mutation in TUBA1A; hydrocephalus, hypoplastic corpus callosum, polymicrogyria, and cerebellar cysts in a patient with a homozygous p.Pro312Leu mutation in POMGNT1. CONCLUSION: DCC, TUBB3, TUBB, TUBA1A, POMGNT1 cause abnormal axonal guidance via different mechanisms and result in congenital mirror movements associated with brain malformations.

Clinical phenotypes of infantile onset CACNA1A-related disorder.

BACKGROUND: CACNA1A-related disorders present with persistent progressive and non-progressive cerebellar ataxia and paroxysmal events: epileptic seizures and non-epileptic attacks. These phenotypes overlap and co-exist in the majority of patients. OBJECTIVE: To describe phenotypes in infantile onset CACNA1A-related disorder and to explore intra-familial variations and genotype-phenotype correlations. MATERIAL AND METHODS: This study was a multicenter international collaboration. A retrospective chart review of CACNA1A patients was performed. Clinical, radiological, and genetic data were collected and analyzed in 47 patients with infantile-onset disorder. RESULTS: Paroxysmal non-epileptic events (PNEE) were observed in 68% of infants, with paroxysmal tonic upward gaze (PTU) noticed in 47% of infants. Congenital cerebellar ataxia (CCA) was diagnosed in 51% of patients including four patients with developmental delay and only one neurological sign. PNEEs were found in 63% of patients at follow-up, with episodic ataxia (EA) in 40% of the sample. Cerebellar ataxia was found in 58% of the patients at follow-up. Four patients had epilepsy in infancy and nine in childhood. Seven infants had febrile convulsions, three of which developed epilepsy later; all three patients had CCA. Cognitive difficulties were demonstrated in 70% of the children. Cerebellar atrophy was found in only one infant but was depicted in 64% of MRIs after age two. CONCLUSIONS: Nearly all of the infants had CCA, PNEE or both. Cognitive difficulties were frequent and appeared to be associated with CCA. Epilepsy was more frequent after age two. Febrile convulsions in association with CCA may indicate risk of epilepsy in later childhood. Brain MRI was normal in infancy. There were no genotype-phenotype correlations found.

Infantile onset progressive cerebellar atrophy and anterior horn cell Degeneration-A novel phenotype associated with mutations in the PLA2G6 gene.

Pontocerebellar hypoplasia (PCH) encompasses a group of neurodegenerative disorders. There are ten known subtypes with common characteristics of pontine and cerebellar hypoplasia or atrophy, neocortical atrophy, and microcephaly. PCH is associated with anterior horn cell degeneration in PCH1a and PCH1b due to mutations in the VRK1 and EXOSC3 genes. Late onset PCH1 has been described in single case reports. The molecular etiology remains mostly unknown. We describe two siblings from a consanguineous Moslem Arabic family with a unique combination of progressive cerebellar atrophy and a SMA-like anterior horn cell degeneration due to a homozygous mutation in the PLA2G6 gene (NM_003560.2). The PLA2G6 gene encodes phospholipase A2 beta, which is involved in the remodeling of membrane phospholipids, signal transduction and calcium signaling, cell proliferation and apoptosis. Mutations in PLA2G6 are known to cause Neurodegeneration with brain iron accumulation 2 (NBIA2): Our patients have some similarities with NBIA2; both are characterized by rapidly progressive psychomotor regression and cerebellar atrophy. However, NBIA2 is not known to exhibit anterior horn cell degeneration. Our patients' phenotype is more consistent with late onset PCH1; thus, indicating that the spectrum of clinical and radiological presentations of PLA2G6 mutations should be extended and that this gene should be included in the molecular evaluation of patients with late onset PCH1.