Novel PANK2 Mutations in Patients With Pantothenate Kinase-Associated Neurodegeneration and the Genotype-Phenotype Correlation.

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare genetic disorder caused by mutations in the mitochondrial pantothenate kinase 2 (PANK2) gene and displays an inherited autosomal recessive pattern. In this study, we identified eight PANK2 mutations, including three novel mutations (c.1103A > G/p.D368G, c.1696C > G/p.L566V, and c.1470delC/p.R490fs494X), in seven unrelated families with PKAN. All the patients showed an eye-of-the-tiger sign on the MRI, six of seven patients had dystonia, and two of seven patients had Parkinsonism. Biallelic mutations of PANK2 decreased PANK2 protein expression and reduced mitochondrial membrane potential in human embryonic kidney (HEK) 293T cells. The biallelic mutations from patients with early-onset PKAN, a severity phenotype, showed decreased mitochondrial membrane potential more than that from late-onset patients. We systematically reviewed all the reported patients with PKAN with PANK2 mutations. The results indicated that the early-onset patients carried a significantly higher frequency of biallelic loss-of-function (LoF) mutations compared to late-onset patients. In general, patients with LoF mutations showed more severe phenotypes, including earlier onset age and loss of gait. Although there was no significant difference in the frequency of biallelic missense mutations between the early-onset and late-onset patients, we found that patients with missense mutations in the mitochondrial trafficking domain (transit peptide/mitochondrial domain) of PANK2 exhibited the earliest onset age when compared to patients with mutations in the other two domains. Taken together, this study reports three novel mutations and indicates a correlation between the phenotype and mitochondrial dysfunction. This provides new insight for evaluating the clinical severity of patients based on the degree of mitochondrial dysfunction and suggests genetic counseling not just generalized identification of mutated PANK2 in clinics.

CHD4 variants are associated with childhood idiopathic epilepsy with sinus arrhythmia.

AIMS: CHD4 gene, encoding chromodomain helicase DNA-binding protein 4, is a vital gene for fetal development. In this study, we aimed to explore the association between CHD4 variants and idiopathic epilepsy. METHODS: Trios-based whole-exome sequencing was performed in a cohort of 482 patients with childhood idiopathic epilepsy. The Clinical Validity Framework of ClinGen and an evaluating method from five clinical-genetic aspects were used to determine the association between CHD4 variants and epilepsy. RESULTS: Four novel heterozygous missense mutations in CHD4, including two de novo mutations (c.1597A>G/p.K533E and c.4936G>A/p.E1646K) and two inherited mutations with co-segregation (c.856C>G/p.P286A and c.4977C>G/p.D1659E), were identified in four unrelated families with eight individuals affected. Seven affected individuals had sinus arrhythmia. From the molecular sub-regional point of view, the missense mutations located in the central regions from SNF2-like region to DUF1087 domain were associated with multisystem developmental disorders, while idiopathic epilepsy-related mutations were outside this region. Strong evidence from ClinGen Clinical Validity Framework and evidences from four of the five clinical-genetic aspects suggested an association between CHD4 variants and epilepsy. CONCLUSIONS: CHD4 was potentially a candidate pathogenic gene of childhood idiopathic epilepsy with arrhythmia. The molecular sub-regional effect of CHD4 mutations helped explaining the mechanisms underlying phenotypic variations.

Ataxia with novel compound heterozygous PEX10 mutations and a literature review of PEX10-related peroxisome biogenesis disorders.

OBJECTIVES: To describe the clinical and genetic features of a Chinese peroxisome biogenesis disorder 6B patient with PEX10 mutations and review PEX10-related peroxisomal disorders. PATIENTS AND METHODS: The proband is a 7-year-old boy with mild mental retardation and gait instability, intention tremor and nystagmus. An extensive clinical and laboratory evaluation including molecular genetic studies was performed. Genomic DNA was extracted from peripheral blood using the standardized phenol/chloroform extraction method, and the coding region of the PEX10 gene was sequenced in three family members. RESULTS: Cerebral MRI showed cerebellar atrophy. Magnetic resonance spectroscopy revealed a decreased N-acetyl aspartate peak in the cerebellum. Nerve conduction velocity examination found prolonged motor and sensory nerve potential latencies (proximal obvious), decreased potential amplitude, and slow nerve conduction velocity. Routine blood tests and biochemistries were abnormal. The PEX10 gene test showed compound heterozygous mutations (c.209 G > A, p. G70E and c.830 T > C, p. L277 P). The mutation c.830 T > C, p. L277 P has been previously reported, whereas c.209 G > A, p. G70E is novel. CONCLUSION: We identified an ataxia case of peroxisome biogenesis disorder 6B caused by novel compound heterozygous mutations of the PEX10 gene. Peroxisome biogenesis disorders should be considered in the differential diagnosis of autosomal recessive ataxia, especially cases with early onset.

[Efficacy and safety of cyclophosphamide as a sequential immunotherapy drug for anti-N-methyl-D-aspartate receptor encephalitis in children].

OBJECTIVE: To evaluate the efficacy and safety of cyclophosphamide as a second-line drug in the treatment of children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. METHODS: Six children with anti-NMDAR encephalitis, who showed poor response to steroids and intravenous immunoglobulin, were given cyclophosphamide as a second-line immunotherapy. Follow-up was performed to evaluate the efficacy and safety of cyclophosphamide. RESULTS: After first-line immunotherapy for 1-4 weeks, the six patients had reduced psychiatric symptoms, seizures, and involuntary movements; three patients had an improved level of consciousness and were able to make simple conversations. However, all the patients still showed slow response, as well as cortical dysfunction symptoms such as aphasia, alexia, agraphia, acalculia, apraxia, and movement disorders. The six patients continued to receive cyclophosphamide as a sequential therapy. They were able to answer simple questions 7 days after treatment. Three school-aged patients were able to make simple calculation, had greatly improved reading and writing ability, and almost recovered self-care ability 2-3 weeks later. The cognitive function of the six patients was almost restored to the level before the onset of disease, and their living ability returned to normal 2-3 months later. During the treatment period, there were no adverse reactions or abnormal results of routine blood test and liver and kidney function tests. CONCLUSIONS: Children with anti-NMDAR encephalitis should be given appropriate immunotherapy as soon as possible. Cyclophosphamide as a sequential therapy has good efficacy and safety.

Comparison of serum apolipoprotein A-I between Chinese multiple sclerosis and other related autoimmune disease.

BACKGROUND: Serum apolipoprotein (apo) A-I was considered to be an immune regulator and could suppress pro-inflammatory cytokines generated by activated T cell in some autoimmune diseases. However, the change of serum apoA-I levels in multiple sclerosis (MS) patients is unknown. METHODS: In the presentation we performed a study on serum apoA-I levels in the patients with MS. We enrolled some age and gender matched patients with MS, autoimmune demyelinating diseases (Guillain-Barre Syndrome and Clinically Isolated Syndrome), neuroinflammatory diseases (viral encephalitis), autoimmune connective diseases (rheumatoid arthritis and systemic lupus erythematosus) and healthy control groups, and tested their serum lipids levels: total cholesterol (TC), triglyceride (TG), high-density lipoproteins (HDL), apolipoproteinB100 (apoB100), apolipoproteinA-I (apoA-I). RESULTS: For all patients, age had no effect on serum apoA-I levels (P > 0.05). Meanwhile, we proved the highest serum apoA-I levels in MS patients and the lowest serum apoA-I levels in SLE patients. Serum apoA-I levels was significantly elevated in female MS patients (P = 0.033; P < 0.05). CONCLUSION: In short we believed that patients with MS and other autoimmune demyelination had significantly decreased serum levels of apo A-I.

Analysis of SCA2 and SCA3/MJD repeats in Parkinson's disease in mainland China: genetic, clinical, and positron emission tomography findings.

To investigate the prevalence and clinical feature(s) of Parkinson's disease (PD) patients with expanded (ATXN2 and MJD1) genes of spinocerebellar ataxia type 2 and 3 (SCA2 and SCA3/MJD) in a mainland Chinese population, CAG triplet repeat expansions of (SCA2 and SCA3/MJD) genes (ATXN2 and MJD1) were analyzed in a cohort of 452 PD patients, including 386 sporadic and 66 familial forms. Striatal dopamine transporter was evaluated in two SCA2 and two SCA3/MJD-positive family members, an idiopathic PD patient and a healthy control using carbon (C11) [(11)C]-radiolabeled-CFT positron emission tomography (PET). We found two patients in one familial PD (FPD) family (1.5%) and two sporadic PD patients (0.5%) with expanded CAG repeats in the ATXN2 locus, four patients in two FPD families (3%) and another three sporadic PD patients (0.8%) in the MJD1 locus. [(11)C]-CFT PET in detected members in SCA2 and SCA3/MJD families showed decrements of (11)C-CFT uptake. These findings suggest that a mutation in SCA2 or SCA3/MJD may be one of the genetic causes of PD.

[Clinical manifestations and detection of pantothenate kinase 2 gene mutation in a patient with Hallervorden-Spatz syndrome].

OBJECTIVE: To investigate the clinical features and detection of pantothenate kinase 2 (PANK2) gene mutation in a Chinese patient with Hallervorden-Spatz syndrome (HSS). METHODS: The clinical features were analyzed in one HSS patient. PANK2 gene mutations were detected by polymerase chain reaction (PCR) and DNA sequence analysis in this patient, her parents and 50 unrelated healthy persons. RESULTS: The main symptoms of this patient were involuntary movements, dysarthria and progressive course. MRI scans showed hypointensity with a central region of hyperintensity in medial globus pallidus on T2 and T2-weighted fluid attenuated inversion recovery (FLAIR) images, i.e. "eye-of-the-tiger" sign. Novel compound heterozygous PANK2 gene mutations, G115T and A803G, were found in this patient, leading to substitution of a glutamic acid for a premature stop codon at amino acid 39 (E39X) and an aspartic acid for glycine codon at amino acid 268 (D268G) respectively. The father was a heterozygote for G115T mutation and the mother a heterozygote for A803G mutation. CONCLUSION: PANK2 gene mutations are present in Chinese HSS patients. And A803G mutation of PANK2 gene is probably a hot spot.

[Frequency of different subtypes of spinocerebellar ataxia in the Han nationality of Hunan province in China].

OBJECTIVE: To determine the frequency of different subtypes of spinocerebellar ataxias (SCAs) in the Han nationality of Hunan province in China. METHODS: The mutations of SCA1, SCA2, SCA3, SCA6, SCA7, SCA17, and dentatorulral-pallidoluysian (DRPLA) were detected with the polymerase chain reaction (PCR), denaturing polyacrylamide gel and DNA sequencing techniques in 139 autosomal dominant SCA families and 61 sporadic SCA patients. RESULTS: Of the 139 families, 11 (7.9%) were positive for SCA1, 9(6.5%) were positive for SCA2, 71 (51.1%) were positive for SCA3, 4 (2.9%) were positive for SCA6, 2 (1.4%) were positive for SCA7, and none was positive for SCA17 and DRPLA. There was 1 SCA2 patient, 3 SCA3 patients, 1 SCA6 patient in the 61 sporadic SCA patients. CONCLUSION: The frequency of SCA3 is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA patients in the Han nationality of Hunan province. SCA6 and SCA7 are rare subtypes.

[Clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 7: study of 3 Chinese families].

OBJECTIVE: To study the clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 7 (SCA7). METHODS: Peripheral blood samples were collected from 245 with autosomal dominant SCA from 184 families and 71 sporadic SCA patients. Polymerase chain reaction, polyacrylamide gel electrophoresis, and capillary electrophoresis technique were used to detect the SCA7 (CAG) n trinucleotide repeat mutations. 163 healthy persons were used as controls. The abnormal allele fragments were sequenced by ABI 377 DNA sequencing machine. RESULTS: Three SCA families with 15 patients were identified with a positive rate of 1.6%. DNA sequencing showed that the abnormal SCA7 alleles with CAG repeat were expanded to 38 to 71 repeats, and the normal SCA7 alleles were carried from 6 to 15 CAG repeats. Analysis of parent-child couples demonstrated the existence of marked anticipation in 2 families, especially in paternal transmission. Linkage analysis found a maximum two-point LOD score of 2.82 in the microsatellite D3S1300 at recombination fraction (theta = 0.00). CONCLUSION: CAG expansion is the pathogenic cause of SCA7, a rare subtype of SCA. The 38 CAG is the minimum pathological expansion in mainland China.