Labrune’s Syndrome Presenting With Stereotypy-Like Movements and Psychosis: A Case Report and Review

Labrune’s syndrome, or leukoencephalopathy with brain calcifications and cysts (LCC), is a rare genetic syndrome with variable neurological presentations. Psychiatric manifestations and involuntary movements are uncommonly reported. We report the case of a 19-year-old female, initially diagnosed with Fahr’s syndrome, who presented to us with acute psychosis, abnormal behavior and involuntary movements. Her brain computed tomography showed extensive bilateral intracranial calcifications without cysts. Genetic testing detected two compound heterozygous variants, NR_033294.1 n.*9C>T and n.24C>T, in the SNORD118 gene, confirming the diagnosis of LCC. We discuss the expanding phenotypic spectrum of LCC and provide a literature review on the current diagnosis and management of this rare syndrome.

Novel mutations associated with carnitine-acylcarnitine translocase and carnitine palmitoyl transferase 2 deficiencies in Malaysia.

OBJECTIVE: Carnitine-acylcarnitine Translocase (CACT) deficiency (OMIM 212138) and carnitine palmitoyl transferase 2 (CPT2) deficiency (OMIM 60065050) are rare inherited disorders of mitochondrial long chain fatty acid oxidation. The aim of our study is to review the clinical, biochemical and molecular characteristics in children diagnosed with CACT and CPT2 deficiencies in Malaysia. DESIGN AND METHODS: This is a retrospective study. We reviewed medical records of six patients diagnosed with CACT and CPT2 deficiencies. They were identified from a selective high-risk screening of 50,579 patients from January 2010 until Jun 2020. RESULTS: All six patients had either elevation of the long chain acylcarnitines and/or an elevated (C16 + C18:1)/C2 acylcarnitine ratio. SLC25A20 gene sequencing of patient 1 and 6 showed a homozygous splice site mutation at c.199-10 T > G in intron 2. Two novel mutations at c.109C > T p. (Arg37*) in exon 2 and at c.706C > T p. (Arg236*) in exon 7 of SLC25A20 gene were found in patient 2. Patient 3 and 4 (siblings) exhibited a compound heterozygous mutation at c.638A > G p. (Asp213Gly) and novel mutation c.1073 T > G p. (Leu358Arg) in exon 4 of CPT2 gene. A significant combined prevalence at 0.01% of CACT and CPT2 deficiencies was found in the symptomatic Malaysian patients. CONCLUSIONS: The use of the (C16 + C18:1)/C2 acylcarnitine ratio in dried blood spot in our experience improves the diagnostic specificity for CACT/CPT2 deficiencies over long chain acylcarnitine (C16 and C18:1) alone. DNA sequencing for both genes aids in confirming the diagnosis.

Molecular analysis of fragile X syndrome (FXS) among Malaysian patients with developmental disability

Fragile X syndrome (FXS) is a neurodevelopmental disorder commonly found worldwide, caused by the silencing of fragile X mental retardation 1 (FMR1) gene on the X-chromosome. Most of the patients lost FMR1 function due to an expansion of cytosine-guanine-guanine (CGG) repeat at the 5’ untranslated region (5’UTR) of the gene. The purpose of this study is to identify the prevalence of FXS and characterize the FMR1 gene CGG repeats distribution among children with developmental disability in Malaysia. Genomic DNA of 2201 samples from different ethnicities (Malays, Chinese, Indian and others) of both genders were PCR-amplified from peripheral blood leukocytes based on specific primers at 5’UTR of FMR1 gene. Full mutations and mosaics were successfully identified by triple methylation specific PCR (ms-PCR) and subsequently verified with FragilEase kit. The findings revealed for the first time the prevalence of FXS full mutation in children with developmental disability in Malaysia was 3.5%, a slightly higher figure as compared to other countries. Molecular investigation also identified 0.2% and 0.4% probands have permutation and intermediate alleles, respectively. The CGG repeats length observation showed 95% of patients had normal alleles within 11 to 44 CGG repeats; with 29 repeats found most common among Malays and Indians while 28 repeats were most common among Chinese. In conclusion, this is the first report of prevalence and characterisation of CGG repeats that reflects genetic variability among Malaysian ethnic grouping.

Clinical and Mutational Analysis of the GCDH Gene in Malaysian Patients with Glutaric Aciduria Type 1.

Glutaric aciduria type 1 (GA1) is an autosomal recessive metabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase enzyme encoded by the GCDH gene. In this study, we presented the clinical and molecular findings of seven GA1 patients in Malaysia. All the patients were symptomatic from infancy and diagnosed clinically from large excretion of glutaric and 3-hydroxyglutaric acids. Bidirectional sequencing of the GCDH gene revealed ten mutations, three of which were novel (Gln76Pro, Glu131Val, and Gly390Trp). The spectrum of mutations included eight missense mutations, a nonsense mutation, and a splice site mutation. Two mutations (Gln76Pro and Arg386Gln) were homozygous in two patients with parental consanguinity. All mutations were predicted to be disease causing by MutationTaster2. In conclusion, this is the first report of both clinical and molecular aspects of GA1 in Malaysian patients. Despite the lack of genotype and phenotype correlation, early diagnosis and timely treatment remained the most important determinant of patient outcome.

Clinical course of sly syndrome (mucopolysaccharidosis type VII).

BACKGROUND: Mucopolysaccharidosis VII (MPS VII) is an ultra-rare disease characterised by the deficiency of ß-glucuronidase (GUS). Patients' phenotypes vary from severe forms with hydrops fetalis, skeletal dysplasia and mental retardation to milder forms with fewer manifestations and mild skeletal abnormalities. Accurate assessments on the frequency and clinical characteristics of the disease have been scarce. The aim of this study was to collect such data. METHODS: We have conducted a survey of physicians to document the medical history of patients with MPS VII. The survey included anonymous information on patient demographics, family history, mode of diagnosis, age of onset, signs and symptoms, severity, management, clinical features and natural progression of the disease. RESULTS: We collected information on 56 patients from 11 countries. Patients with MPS VII were classified based on their phenotype into three different groups: (1) neonatal non-immune hydrops fetalis (NIHF) (n=10), (2) Infantile or adolescent form with history of hydrops fetalis (n=13) and (3) Infantile or adolescent form without known hydrops fetalis (n=33). Thirteen patients with MPS VII who had the infantile form with history of hydrops fetalis and survived childhood, had a wide range of clinical manifestations from mild to severe. Five patients underwent bone marrow transplantation and one patient underwent enzyme replacement therapy with recombinant human GUS. CONCLUSIONS: MPS VII is a pan-ethnic inherited lysosomal storage disease with considerable phenotypical heterogeneity. Most patients have short stature, skeletal dysplasia, hepatosplenomegaly, hernias, cardiac involvement, pulmonary insufficiency and cognitive impairment. In these respects it resembles MPS I and MPS II. In MPS VII, however, one unique and distinguishing clinical feature is the unexpectedly high proportion of patients (41%) that had a history of NIHF. Presence of NIHF does not, by itself, predict the eventual severity of the clinical course, if the patient survives infancy.

Mutation analysis of glycine decarboxylase, aminomethyltransferase and glycine cleavage system protein-H genes in 13 unrelated families with glycine encephalopathy.

Glycine encephalopathy (GCE) or nonketotic hyperglycinemia is an inborn error of glycine metabolism, inherited in an autosomal recessive manner due to a defect in any one of the four enzymes aminomethyltransferase (AMT), glycine decarboxylase (GLDC), glycine cleavage system protein-H (GCSH) and dehydrolipoamide dehydrogenase in the glycine cleavage system. This defect leads to glycine accumulation in body tissues, including the brain, and causes various neurological symptoms such as encephalopathy, hypotonia, apnea, intractable seizures and possible death. We screened 14 patients from 13 families with clinical and biochemical features suggestive of GCE for mutation in AMT, GLDC and GCSH genes by direct sequencing and genomic rearrangement of GLDC gene using a multiplex ligation-dependant probe amplification. We identified mutations in all 14 patients. Seven patients (50%) have biallelic mutations in GLDC gene, six patients (43%) have biallelic mutations in AMT gene and one patient (7%) has mutation identified in only one allele in GLDC gene. Majority of the mutations in GLDC and AMT were missense mutations and family specific. Interestingly, two mutations p.Arg265His in AMT gene and p.His651Arg in GLDC gene occurred in the Penan sub-population. No mutation was found in GCSH gene. We concluded that mutations in both GLDC and AMT genes are the main cause of GCE in Malaysian population.

Late-Onset Glycogen Storage Disease Type II (Pompe's Disease) with a Novel Mutation: A Malaysian Experience.

Pompe's disease (acid maltase deficiency, glycogen storage disease type II) is an autosomal recessive disorder caused by a deficiency of lysosomal acid α-1,4-glucosidase, resulting in excessive accumulation of glycogen in the lysosomes and cytoplasm of all tissues, most notably in skeletal muscles. We present a case of adult-onset Pompe's disease with progressive proximal muscles weakness over 5 years and respiratory failure on admission, requiring prolonged mechanical ventilation. Electromyography showed evidence of myopathic process with small amplitudes, polyphasic motor unit action potentials, and presence of pseudomyotonic discharges. Muscle biopsy showed glycogen-containing vacuoles in the muscle fibers consistent with glycogen storage disease. Genetic analysis revealed two compound heterozygous mutations at c.444C>G (p.Tyr148∗) in exon 2 and c.2238G>C (p.Trp746Cys) in exon 16, with the former being a novel mutation. This mutation has not been reported before, to our knowledge. The patient was treated with high protein diet during the admission and subsequently showed good clinical response to enzyme replacement therapy with survival now to the eighth year. Conclusion. In patients with late-onset adult Pompe's disease, careful evaluation and early identification of the disease and its treatment with high protein diet and enzyme replacement therapy improve muscle function and have beneficial impact on long term survival.

Biochemical profiling in two siblings with mitochondrial 2-methylacetoacetyl-CoA thiolase deficiency

We report the biochemical profiling in two siblings with mitochondrial 2-methylacetoacetyl-CoA thiolase deficiency. Organic aciduria typical of this rare inborn error metabolism was found when the elder sibling presented with an episode of severe ketoacidosis at 20 months of age, which consisted of excessive excretion of ketones, tiglylglycine, 2-methyl-3-hydroxybutyrate, and 2-methylacetoacetate. Blood acylcarnitiness profile showed elevation of C5OH-carnitine, which represents 2-methyl-3-hydroxybutyrylcarnitine. A similar biochemical profile was identified in the younger sibling during screening although he had only mild clinical symptoms. Both patients reported a favourable outcome on follow-up.