Gene Distribution in Pediatric-Onset Inherited Peripheral Neuropathy: A Single Tertiary Center in Thailand.

BACKGROUND: Inherited peripheral neuropathy presents a diagnostic and therapeutic challenge due to its association with mutations in over 100 genes. This condition leads to long-term disability and poses a substantial healthcare burden on society. OBJECTIVE: This study aimed to investigate the distribution of genes and establish the genotype-phenotype correlations, focusing on pediatric-onset cases. METHODS: Exome sequencing and other analytical techniques were employed to identify pathogenic variants, including duplication analysis of the PMP22 gene. Each patient underwent physical examination and electrophysiological studies. Genotypes were correlated with phenotypic features, such as age at disease onset and ulnar motor nerve conduction velocity. RESULTS: We identified 35 patients with pediatric-onset inherited peripheral neuropathy. Pathogenic or likely pathogenic variants were confirmed in 24 out of 35 (68.6%) patients, with 4 of these variants being novel. A confirmed molecular diagnosis was achieved in 90.9% (10/11) of patients with demyelinating Charcot-Marie-Tooth disease (CMT) and 56.3% (9/16) of patients with axonal CMT. Among patients with infantile-onset CMT (≤2 years), the most common causative genes were MFN2 and NEFL, while GDAP1 and MFN2 were frequent causes among patients with childhood- or adolescent-onset CMT (3-9 years). CONCLUSIONS: The MFN2 gene was the most commonly implicated gene, and the axonal type was predominant in this cohort of Thai patients with pediatric-onset inherited peripheral neuropathy.

Incidence and associated factors of congenital syphilis at a tertiary care center in Thailand.

Background: The incidence of congenital syphilis is increasing worldwide, in parallel with the increase of syphilis in the general population. Objectives: This study aimed to determine the incidence and risk factors for congenital syphilis at a referral tertiary care center in Bangkok, Thailand. Methods: This is a case-control study using the hospital medical records of neonates born at our hospital, whose mothers had confirmed syphilis during pregnancy or at delivery between 2011 and 2018. Maternal and neonatal data were reviewed. Neonates were categorized into congenital syphilis according to CDC surveillance case definition for congenital syphilis 2015 and the American Academy of Pediatrics Congenital Syphilis 2018: confirmed and probable were assigned to the case group, while possible and less likely congenital syphilis were used as the control group. Factors associated with congenital syphilis were analyzed using univariable and multivariable analysis. Results: Among 19,558 live births, there were 126 neonates born to mothers with syphilis. Almost 40% of mothers were teenage mothers and 48.4% had inadequate or no syphilis treatment. Forty neonates met the criteria of congenital syphilis giving the incidence of 204 per 100,000 live births (95% confidence interval [CI]: 146-278). Factors associated with congenital syphilis were inadequate treatment of maternal syphilis and preterm birth (adjusted odd ratio [aOR]: 2.69, 95% CI: 1.02-7.11, P = 0.046 and aOR: 2.91; 95% CI: 1.01-8.39, P = 0.049, respectively). Conclusions: The incidence of congenital syphilis in our institution was high. Factors associated with congenital syphilis were inadequate treatment of maternal syphilis and preterm birth. Improvement of prenatal care should be emphasized.

Long-read Nanopore sequencing identified D4Z4 contractions in patients with facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is a genetic muscle disorder caused by abnormal expression of the DUX4 protein, commonly resulting from a contraction of D4Z4 repeat units with the presence of a polyadenylation (polyA) signal. More than 10 units of the D4Z4 repeat, with a length of 3.3 kb per unit, are typically required to silence DUX4 expression. Consequently, molecular diagnosis of FSHD is challenging. We used Oxford Nanopore technology to perform whole-genome sequencing of seven unrelated patients with FSHD, their six unaffected parents, and 10 unaffected controls. All seven patients were successfully identified to harbor one to five D4Z4 repeat units and the polyA signal, whereas none of the 16 unaffected individuals met the molecular diagnostic criteria. Our newly developed method provides a straightforward and powerful molecular diagnostic tool for FSHD.

Utilisation of exome sequencing for muscular disorders in Thai paediatric patients: diagnostic yield and mutational spectrum.

Muscular dystrophies and congenital myopathies are heterogeneous groups of inherited muscular disorders. An accurate diagnosis is challenging due to their complex clinical presentations and genetic heterogeneity. This study aimed to determine the utilisation of exome sequencing (ES) for Thai paediatric patients with muscular disorders. Of 176 paediatric patients suspected of genetic/inherited myopathies, 133 patients received a molecular diagnosis after performing conventional investigations, single gene testing, and gene panels. The remaining 43 patients from 42 families could be classified into three groups: Group 1, MLPA-negative Duchenne muscular dystrophy (DMD) with 9 patients (9/43; 21%), Group 2, other muscular dystrophies (MD) with 18 patients (18/43; 42%) and Group 3, congenital myopathies (CM) with 16 patients (16/43; 37%). All underwent exome sequencing which could identify pathogenic variants in 8/9 (89%), 14/18 (78%), and 8/16 (50%), for each Group, respectively. Overall, the diagnostic yield of ES was 70% (30/43) and 36 pathogenic/likely pathogenic variants in 14 genes were identified. 18 variants have never been previously reported. Molecular diagnoses provided by ES changed management in 22/30 (73%) of the patients. Our study demonstrates the clinical utility and implications of ES in inherited myopathies.

Neuronal Ceroid Lipofuscinoses Presenting as Rett-like Phenotype: A Two-Case Report From Thailand.

BACKGROUND: Neuronal ceroid lipofuscinoses (NCLs) (hereafter described as CLN disease) comprise a rare and life-limiting set of genetically inherited neurodegenerative disorders that are characterized by abnormal lysosomal storage. The NCL disorders are, collectively, the most common group of degenerative brain disorders in children. PATIENT DESCRIPTIONS: We report two cases of CLN disease that were diagnosed and treated at the Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Both cases of CLN disease (CLN1 and CLN6 diagnosed in 2016 and 2017, respectively) profiled in this report presented with clinical features of Rett syndrome. In the first case, a 2-year-old girl presented with Rett-like clinical features, including global developmental regression and hand-wringing action. Single-gene analysis of the MECP2 gene was negative. However, PPT1 gene sequencing revealed a novel homozygous frameshift mutation, c.629_630dupGT (p.Ile211Valfs∗10). In the second case, a 7.5-year-old girl presented with ataxia, progressive myoclonic epilepsy, and Rett-like hand-wringing. A c.794_796delCCT variant in the CLN6 gene was identified by whole-exome sequencing. Fingerprint bodies from electron microscopy of the skin also supported a diagnosis of CLN disease in our second case. DISCUSSION: Presentation with clinical features of Rett syndrome has only been reported in patients diagnosed with CLN1 and CLN7 disease, and never in those with CLN6. CONCLUSIONS: Physicians should suspect and investigate for CLN disease in patients with Rett-like phenotype who are negative for MECP2 mutation, especially in patients with visual impairment and early prominent brain atrophy.

Polyneuritis Cranialis Associated with BNT162b2 mRNA COVID-19 Vaccine in a Healthy Adolescent.

A 16-year-old Thai girl developed right facial palsy, a lower motor neuron lesion, and numbness 3 h after receiving the first dose of the BNT162b2 mRNA vaccine. Neurological examination showed the involvement of the right cranial nerves (CN) V, VII, IX, and X. Electrophysiological tests revealed the absence of an F wave response, suggesting a proximal demyelinating process. Magnetic resonance imaging of the brain demonstrated abnormal enhancement of the right CN VII. The cerebrospinal fluid profile on day 7 after the onset of symptoms was normal. The patient was diagnosed with polyneuritis cranialis, a rare variant of Guillain-Barre syndrome. She was successfully treated with intravenous immunoglobulin therapy.