SOD2 Alleviates Hearing Loss Induced by Noise and Kanamycin in Mitochondrial DNA4834-deficient Rats by Regulating PI3K/MAPK Signaling.

Superoxide dismutase 2 (SOD2)-mediated gene therapy has significant protective effects against kanamycin-induced hearing loss and hair cell loss in the inner ear, but the underlying mechanisms are still unclear. Herein, an in vivo aging model of mitochondrial DNA (mtDNA)4834 deletion mutation was established using D-galactose, and the effects of noise or kanamycin on inner ear injury was investigated. Rats subjected to mtDNA4834 mutation via D-galactose administration showed hearing loss characterized by the disruption of inner ear structure (abnormal cell morphology, hair cell lysis, and the absence of the organ of Corti), increased SOD2 promoter methylation, and an increase in the degree of apoptosis. Exposure to noise or kanamycin further contributed to the effects of D-galactose. SOD2 overexpression induced by viral injection accordingly counteracted the effects of noise and kanamycin and ameliorated the symptoms of hearing loss, suggesting the critical involvement of SOD2 in preventing deafness and hearing-related conditions. The PI3K and MAPK signaling pathways were also regulated by noise/kanamycin exposure and/or SOD2 overexpression, indicating that they may be involved in the therapeutic effect of SOD2 against age-related hearing loss.

Acute urinary retention in the first and second-trimester of pregnancy: Three case reports.

BACKGROUND: Acute urinary retention (AUR) is rare during pregnancy. CASE SUMMARY: We report on three pregnant women with AUR between the 10th and 18th wk of gestation. Case 1 was first diagnosed as urinary tract infection and developed a urinary tract infection due to urinary retention caused by urethral obstruction. Case 2 had a history of previous abdominal surgery for pelvic tuberculosis, leading to severe adhesions and a persistent retroverted uterus. In case 3, healthcare providers focused on the patient's gastrointestinal symptoms and did not investigate her inability to void. Case 1 required manual disimpaction of the uterus and the knee-chest position. The other cases required immediate catheterization. The condition resolved in cases 1 and 2; these patients had normal pregnancies. Case 3 had severe complications at the time of consultation, leading to an abortion. CONCLUSION: Retroverted uterus is the most common cause of AUR. Prompt recognition and diagnosis are required. Clinicians should be aware of the risk factors, etiology, and clinical presentation of AUR in the first and second trimester of pregnancy.

A novel delins (c.773_819+47delinsAA) mutation of the PCCA gene associated with neonatal-onset propionic acidemia: a case report.

BACKGROUND: Propionic acidemia (PA)(OMIM#606054) is an inborn error of branched-chain amino acid metabolism, caused by defects in the propionyl-CoA carboxylase (PCC) enzyme which encoded by the PCCA and PCCB genes. CASE PRESENTATION: Here we report a Chinese neonate diagnosed with suspected PA based on the clinical symptoms, gas chromatography-mass spectrometry (GC/MS), and brain imaging tests. Targeted next-generation sequencing (NGS) was performed on the proband. We detected only one heterozygous recurrent nonsense variant (c.937C > T, p.Arg313Ter) in the PCCA gene. When we manually checked the binary alignment map (BAM) diagram of PCCA gene, we found a heterozygous deletion chr13:100915039-100915132delinsAA (c.773_819 + 47delinsAA) (GRCh37.p13) inside the exon 10 in the PCCA gene. The results were validated by Sanger sequencing and qPCR method in the family: the variant (c.937C > T, p.Arg313Ter) was in the maternal allele, and the delins was in the paternal allele. When the mother was pregnant again, prenatal diagnosis was carried out through amniocentesis at 18 weeks gestation, the fetus carried neither of the two mutations. After birth, newborn screening was undertaken, the result was negative. CONCLUSIONS: We identified a recurrent c.937C > T and a novel c.773_819 + 47delinsAA mutations in the PCCA gene, which may be the genetic cause of the phenotype of this patient. Our findings expanded the spectrum of causative genotype-phenotype of the PCCA gene. For the cases, the NGS results revealed only a heterozygous mutation in autosomal recessive disease when the gene is associated with phenotypes, it is necessary to manually check the BAM diagram to improve the detection rate. Targeted NGS is an effective technique to detect the various genetic lesions responsible for the PA in one step. Genetic testing is essential for genetic counselling and prenatal diagnosis in the family to avoid birth defects.

[Clinical phenotype and genetic analysis of MED13L syndrome].

A boy aged 4 years and 2 months was found to have delayed language and motor development, instability of gait, poor eye contact, stereotyped behavior, and seizure at the age of 3 years. Physical examination showed special facial features, including plagiocephaly, blepharoptosis, wide nasal bridge, down-turned mouth corners at both sides, and low-set ears. There were only two knuckles at the little finger of the left hand. The anteroposterior and lateral films of the spine showed scoliosis; echocardiography showed ventricular septal defect; the Gesell Developmental Scale showed delayed language development and moderate intellectual disability; there were no abnormalities in the karyotype; genome-wide SNP arrays found a duplication in 12q24.21 region with a size of 1.03 Mb in chromosome 12, while this was not seen in his parents. The boy was diagnosed with MED13L syndrome. Point mutation, deletion, and duplication in the MED13L gene can lead to MED13L syndrome. The patients with different genotypes may have different phenotypes. Genome-wide SNP arrays may help with the diagnosis of this disease.

HLA-A*24:02 as a common risk factor for antiepileptic drug-induced cutaneous adverse reactions.

OBJECTIVE: To investigate the involvement of human leukocyte antigen (HLA) loci in aromatic antiepileptic drug-induced cutaneous adverse reactions. METHODS: A case-control study was performed to detect HLA loci involved in aromatic antiepileptic drug-induced Stevens-Johnson syndrome in a southern Han Chinese population. Between January 1, 2006, and December 31, 2015, 91 cases of Stevens-Johnson syndrome induced by aromatic antiepileptic drugs and 322 matched drug-tolerant controls were enrolled from 8 centers. Important genotypes were replicated in cases with maculopapular eruption and in the meta-analyses of data from other populations. Sequence-based typing determined the HLA-A, HLA-B, HLA-C, and HLA-DRB1 genotypes. RESULTS: HLA-B*15:02 was confirmed as strongly associated with carbamazepine-induced Stevens-Johnson syndrome (p = 5.63 × 10-15). In addition, HLA-A*24:02 was associated significantly with Stevens-Johnson syndrome induced by the aromatic antiepileptic drugs as a group (p = 1.02 × 10-5) and by individual drugs (carbamazepine p = 0.015, lamotrigine p = 0.005, phenytoin p = 0.027). Logistic regression analysis revealed a multiplicative interaction between HLA-B*15:02 and HLA-A*24:02. Positivity for HLA-A*24:02 and/or HLA-B*15:02 showed a sensitivity of 72.5% and a specificity of 69.0%. The presence of HLA-A*24:02 in cases with maculopapular exanthema was also significantly higher than in controls (p = 0.023). Meta-analysis of data from Japan, Korea, Malaysia, Mexico, Norway, and China revealed a similar association. CONCLUSIONS: HLA-A*24:02 is a common genetic risk factor for cutaneous adverse reactions induced by aromatic antiepileptic drugs in the southern Han Chinese and possibly other ethnic populations. Pretreatment screening is recommended for people in southern China.

Expression profile of SIX family members correlates with clinic-pathological features and prognosis of breast cancer: A systematic review and meta-analysis.

Sineoculis homeobox homolog (SIX) family proteins, including SIX1, SIX2, SIX3, SIX4, SIX5, and SIX6, have been implicated in the initiation and progression of breast cancer, but the role of each member in breast tumor is not fully understood. We conducted a systematic review and meta-analysis to evaluate the association between the mRNA levels of all 6 members and clinic-pathological characteristics and clinical outcome of breast cancer patients based on the PRISMA statement criteria.ArrayExpress and Oncomine were searched for eligible databases published up to December 10, 2015. The association between the mRNA expression of SIX family members and clinic-pathological features and prognosis was measured by the odds ratio (OR), hazard ratio (HR), and the corresponding 95% confidence interval (CI), respectively. All statistical analyses were performed using STATA software.In total, 20 published Gene Expression Omnibus (GEO) databases with 3555 patients were analyzed. Our analysis revealed that patients with SIX1 overexpression had worse overall survival (OS) (HR: 1.28, 95% CI: 1.03-1.58) and shorter relapse-free survival (RFS) (HR: 1.28, 95% CI: 1.05-1.56), and much worse prognosis for luminal breast cancer patients with SIX1 overexpression (OS: HR: 1.64, 95% CI: 1.13-2.39; RFS: HR: 1.43, 95% CI: 1.06-1.93). We found that patients with higher SIX2 level had shorter time to both relapse and metastasis. However, high SIX3 mRNA level was a protective factor for OS and RFS of basal-like breast cancer patients.Our study suggested that members of SIX family played distinct roles in breast cancer. Detailed analysis of the expression of the SIX family members might provide useful information to predict breast cancer progression and prognosis.

[Association of mammalian target of rapamycin gene polymorphisms with the risk of pediatric epilepsy].

OBJECTIVE: To study the association between two single nucleotide polymorphisms (SNP), rs2295080 and rs2536, in mammalian target of rapamycin (mTOR) gene and the susceptibility to pediatric epilepsy. METHODS: A case- control study was performed on 480 children with epilepsy (116 cases of refractory epilepsy) and 503 healthy children. SNP rs2295080 and rs2536 in the mTOR gene were detected by polymerase chain reaction restriction and fragment length polymorphisms (PCR-RFLP). Genotype and allele frequencies of SNP rs2295080 and rs2536 were compared between the children with epilepsy and healthy controls. RESULTS: There were no significant differences in the genotype and allele frequencies of SNP rs2295080 between the children with epilepsy and healthy controls. There were no significant differences in the genotype frequencies of SNP rs2536 between the two groups either, but the frequency of G allele of SNP rs2536 was higher in children with epilepsy than that in healthy controls (P=0.042, OR=1.344, 95%CI: 1.010-1.789). CONCLUSIONS: SNP rs2536 of mTOR gene may be associated with the risk of pediatric epilepsy.

Impact of SLCO1B1 521T > C variant on leucovorin rescue and risk of relapse in childhood acute lymphoblastic leukemia treated with high-dose methotrexate.

BACKGROUND: Recent studies suggest that SLCO1B1 c.521T > C variant decreases the clearance of methotrexate (MTX) and elevates its plasma concentration, hence leucovorin doses may need to be adjusted. However, high leucovorin doses may affect the cure rate in childhood acute lymphoblastic leukemia (ALL). Hitherto neither the appropriate dose of leucovorin in carriers of SLCO1B1 c.521T > C variant nor the impact of SLCO1B1 polymorphism on the risk of ALL relapse has been clarified. PROCEDURE: A double-blind and controlled study was conducted in 136 children with ALL. They were genotyped for rs4149056 single nucleotide polymorphism into wild-type group and variant group, and received MTX at 3-5 g/m(2) . Plasma concentration MTX and its metabolite were determined by HPLC. The toxicity of MTX, dose of leucovorin and 5-year relapse rate of ALL were recorded. RESULTS: Compared with wild-type group, area under the concentration time curve of MTX increased by 4.2-fold and peripheral clearance rate decreased significantly in variant group. Patients carrying rs4149056 C allele endured a remarkable longer time above the MTX safety threshold and suffered from a higher frequency of toxicity, so 2.2-fold leucovorin was given. However, no association was found between SLCO1B1 c.521T > C variant and the relapse risk in five years. CONCLUSIONS: The SLCO1B1 c.521T > C variant was an important determinant of MTX disposition and their carriers were exposed to increased intensity and time of MTX. An appropriate leucovorin dose raise in variant group was beneficial to reducing the serious toxicity. The c.521T > C variant wasn't associated with the risk of ALL relapse.

[Clinical features and MECP2 mutations in children with Rett syndrome].

OBJECTIVE: To study the clinical features and mutations in methyl-CpG-binding protein 2 (MECP2) gene among children with classical Rett syndrome in China. METHODS: PCR and direct sequencing were employed to analyze the three exons of MECP2 gene in 9 children recently diagnosed with Rett syndrome and their parents. RESULTS: Heterozygous mutations were identified in 5 out of 9 patients, with a mutation rate of over 50%; there was one case of insert mutation (c.913insT) and 4 cases of missense mutation (exon 3: c.316C>T (R106W); exon 4: c.502C>T (R168X), c.808C>T (R270X), and c.1126C>T (P376S). A new mutation (c.913insT) was found. No mutations were detected in their parents. Two patients had MECP2 mutations in the transcriptional repression domain (TRD). They had almost lost language functions and were found to have significantly delayed development compared with other patients. CONCLUSIONS: Mutations in MECP2 gene were detected in 5 confirmed cases of Rett syndrome, and most of them were on exon 4. Mutations in the TRD of MECP2 protein may affect the language ability and development in children with Rett syndrome.

Association of HLA-B*1502 and *1511 allele with antiepileptic drug-induced Stevens-Johnson syndrome in central China.

Previous studies have demonstrated a strong association between carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) and HLA-B*1502 in Han Chinese. Here, we extended the study of HLA-B*1502 susceptibility to two different antiepileptic drugs, oxcarbazepine (OXC) and phenobarbital (PB). In addition, we genotyped HLA-B*1511 in a case of CBZ-induced SJS with genotype negative for HLA-B*1502. The presence of HLA-B*1502 was determined using polymerase chain reaction with sequence-specific primers (PCR-SSP). Moreover, we genotyped HLA-B*1502 in 17 cases of antiepileptic drugs (AEDs)-induced cutaneous adverse drug reactions (cADRs), in comparison with AEDs-tolerant (n=32) and normal controls (n=38) in the central region of China. The data showed that HLA-B*1502 was positive in 5 of 6 cases of AEDs-induced SJS (4 CBZ, 1 OXC and 1 PB), which was significantly more frequent than AEDs-tolerant (2/32, 18 CBZ, 6 PB and 8 OXC) and normal controls (3/38). Compared with AEDs-tolerant and normal controls, the OR for patients carrying the HLA-B*1502 with AEDs-induced SJS was 6.25 (95% CI: 1.06-36.74) and 4.86 (95% CI: 1.01-23.47). The sensitivity and specificity of HLA-B*1502 for prediction of AEDs-induced SJS were 71.4%. The sensitivity and specificity of HLA-B*1502 for prediction of CBZ-induced SJS were 60% and 94%. HLA-B*1502 was not found in 11 children with maculopapular exanthema (MPE) (n=9) and hypersensitivity syndrome (HSS) (n=2). However, we also found one case of CBZ-induced SJS who was negative for HLA-B*1502 but carried HLA-B*1511. It was suggested that the association between the CBZ-induced SJS and HLA-B*1502 allele in Han Chinese children can extend to other aromatic AEDs including OXC and PB related SJS. HLA-B*1511 may be a risk factor for some patients with CBZ-induced SJS negative for HLA-B*1502.

Improved molecular assay for sex identification of the endangered crested Ibis (Nipponia nippon) based on the CHD1 gene and a sex-linked microsatellite locus.

Sex Identification of monomorphic birds, especially endangered avian species, is essential for ecological study and biodiversity conservation. In this study, two popular primer sets of 2550F/2718R and P2/P8, which were designed to amplify different fragments of chromodomain-helicase-DNA binding protein 1 (CHD1) genes mapped on both Z and W chromosomes in birds, were used to identify for the first time the sex of individuals of the endangered species crested ibis (Nipponia nippon) in a large number of samples. An improved primer set of 2467F/2530R was re-designed to be specific to crested ibis following their conserved sequences derived from the 2550F/2718R primers. PCR products of the new primers were conveniently visualized with two bands of 552 base pairs (bp) and 358 bp for females, but a single band of 552 bp for males in routine 1.8% agarose gel. Similarly, the P2/P8 primer set amplified two fragments of 398 bp and 381 bp from females but one fragment of 398 bp from males; however, a high resolution involving 10% Polyacrylamide gel had to be employed to resolve the 17 bp insertions/deletions (in/dels) present between the two amplicons in females. In addition, a microsatellite locus NnNF05 was validated to be sex-linked and shown to be effective in the sexing of crested ibis, supporting its utility in non-invasive sampling. This study provides a rapid, convenient, and reliable molecular assay for improving sex identification in the monomorphic and monogamous crested ibis, and thus facilitates the selection of breeding pairs in captive programs and reintroduction initiatives.

Lack of Structural Variation but Extensive Length Polymorphisms and Heteroplasmic Length Variations in the Mitochondrial DNA Control Region of Highly Inbred Crested Ibis, Nipponia nippon.

The animal mitochondrial DNA (mtDNA) length polymorphism and heteroplasmy are accepted to be universal. Here we report the lack of structural variation but the presence of length polymorphism as well as heteroplasmy in mtDNA control region of an endangered avian species - the Crested Ibis (Nipponia nippon). The complete control region was directly sequenced while the distribution pattern and inheritance of the length variations were examined using both direct sequencing and genotyping of the PCR fragments from captive birds with pedigrees, wild birds and a historical specimen. Our results demonstrated that there was no structural variation in the control region, however, different numbers of short tandem repeats with an identical motif of CA3CA2CA3 at the 3'-end of the control region determined the length polymorphisms among and heteroplasmy within individual birds. There were one to three predominant fragments in every bird; nevertheless multiple minor fragments coexist in all birds. These extremely high polymorphisms were suggested to have derived from the 'replication slippage' of a perfect microsatellite evolution following the step-wise mutational model. The patterns of heteroplasmy were found to be shifted between generations and among siblings but rather stable between blood and feather samples. This study provides the first evidence of a very extensive mtDNA length polymorphism and heteroplasmy in the highly inbred Crested Ibis which carries an mtDNA genome lack of structural genetic diversity. The analysis of pedigreed samples also sheds light on the transmission of mtDNA length heteroplasmy in birds following the genetic bottleneck theory. Further research focusing on the generation and transmission of particular mtDNA heteroplasmy patterns in single germ line of Crested Ibis is encouraged by this study.