Clinical phenotypic and genotypic analysis of 5 pediatric patients with β-ketothiolase deficiency / 中华儿科杂志

Objective: To summarize the clinical and genetic characteristics of children with β-ketothiolase deficiency (BKTD). Methods: The clinical characteristics, biochemical, markers detected by tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC/MS), as well as the variants in ACAT1 gene among 5 children with BKTD in Children's Hospital of Chongqing Medical University between October 2018 and December 2022 were retrospectively analyzed. Results: The onset age of the disease in 5 patients (4 males and 1 female) ranged from 9.7 to 28.0 months. During the acute phase, severe metabolic acidosis was observed with a pH of 6.9-7.1, as well as hypoglycaemia (2.3-3.4 mmol/L) and positive urinary ketone bodies (+-++++). Blood levels of methylcrotonyl carnitine, methylmalonyl carnitine and malonyl carnitine were 0.03-0.42, 0.34-1.43 and 0.83-3.53 μmol/L respectively and were significantly elevated. Urinary 2-methyl-3-hydroxybutyric acid was 22-202 and 3-hydroxybutyric acid was 4-6 066, both were higher than the normal levels. Methylcrotonylglycine was mild elevated (0-29). The metabolites detected by MS/MS and GC/MS were significantly reduced after treatment. Analysis of ACAT1 gene mutation was performed in 5 children. Most variants were missense (8/9). Four previously unreported variants were identified: c.678G>T (p.Trp226Cys), c.302A>G (p.Gln101Arg), c.627_629dupTGA (p.Asn209_Glu210insAsp) and c.316C>T (p.Gln106Ter), the first 2 variants were predicted to be damaging by SIFT, PolyPhen-2 and Mutation Taster software. c.316C>T (p.Gln106Ter) is a nonsense variant. Conclusions: β-ketothiolase deficiency is relatively rare, lacks specific clinical manifestations, however severe metabolic acidosis, hypoglycemia, and ketosis during the acute onset were consistent findings. Missense mutations in the ACAT1 gene are common genetic causes of β-ketothiolase deficiency.

BCS1Neonatal growth retardation and lactic acidosis initiated by novel mutation sites in L gene / 中华预防医学杂志

This study aims to analyze the clinical characteristics and genetic variations of two cases with developmental delay and lactic acidosis in a family, and to explore the relationship between genetic variations and clinical features. A retrospective analysis was conducted on the clinical characteristics of two siblings with developmental delay and lactic acidosis who were treated at the Neonatal Department of Children's Hospital of Chongqing Medical University in May 2019 and December 2021, respectively. Whole-exome sequencing was used to detect genetic variations in the affected children. Homology modeling of the BCS1L protein was performed to analyze the structural and functional changes of the protein. The correlation between genetic variations and clinical phenotypes was analyzed. The results showed that the main clinical features of the two affected children in this family were manifestations of mitochondrial respiratory chain complex Ⅲ deficiency, including prematurity, developmental delay, respiratory failure, lactic acidosis, cholestasis, liver dysfunction, renal tubular lesions, coagulation dysfunction, anemia, hypoglycemia, hypotonia, and early death. Whole-exome sequencing revealed a novel deletion mutation c.486_488delGGA (p.E163del) and a novel missense mutation c.992C>T (p.T331I) in the BCS1L gene. Structural analysis of the homology modeling showed that the compound heterozygous mutation had a significant impact on protein function. In conclusion, the novel mutation site c.992C>T (p.T331I) in the BCS1L gene is a "likely pathogenic" mutation, and the compound heterozygous mutation is closely related to the phenotype of mitochondrial respiratory chain complex Ⅲ deficiency.

The Expression of BTG2 and Its Regulatory Effect on Radiosensitivity of Lung Adenocarcinoma / 中国生物化学与分子生物学报

Among the types of lung cancer, lung adenocarcinoma accounts for the majority, and its overall survival rate is poor. B-cell translocation gene 2 (BTG2) is a member of the antiproliferative gene family, belonging to the BTG/TOB family. Many studies have shown that BTG2 was abnormally expressed in many types of tumors, but its regulatory role in the radiosensitivity of lung adenocarcinoma remained unclear. In this study, we explored the expression level of BTG2 in patients with lung adenocarcinoma and its correlation with clinical prognosis through online database and tissue samples of lung adenocarcinoma patient. The results indicated that the expression level of BTG2 decreased significantly in lung adenocarcinoma patient with radiation resistance. Bioinformatics analysis confirmed that BTG2 could respond to radiotherapy in lung adenocarcinoma cell lines, and its low expression in lung adenocarcinoma patients was associated with poor prognosis (P < 0.05). The lentivirus overexpressing BTG2 (OE-BTG2) was transfected into human lung adenocarcinoma cell lines to increase the expression level of BTG2 including A549 and H1299. And the effect of BTG2 overexpression on the radiosensitivity of lung adenocarcinoma cell lines was detected by clone formation assay. Clone formation experiment confirmed that overexpression of BTG2 could significantly enhance the radiosensitivity of A549 and H1299 cell lines (P < 0.05). The expression levels of BTG2 and apoptosis related protein-Bax were detected by Western blotting (WB) and immunohistochemistry (IHC). The effect of BTG2 on radiation sensitivity of lung adenocarcinoma was further detected via nude mouse in vivo. WB experiment confirmed that BTG2 upregulation could significantly increase the apoptosis level of A549 and H1299 cells after radiation. Moreover, BTG2 overexpression can markedly enhance the radiosensitivity of lung adenocarcinoma (P < 0.05) and increase the protein level of Bax after radiation in vivo. In conclusion, BTG2 had low expression in lung adenocarcinoma patients and its low expression level was closely related to the poor clinical prognosis. Overexpression of BTG2 can increase the radiosensitivity of lung adenocarcinoma cell lines and promote the process of apoptosis after radiation, indicating a new target for overcoming the radiation resistance of lung adenocarcinoma.

Association between body mass index and lung function in children with asthma after corticosteroids inhalation / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the association between body mass index (BMI) and lung function of asthmatic children after inhaling corticosteroids (ICS).</p><p><b>METHODS</b>One hundred and fifty-seven children with asthma were classified into obese (46 cases), over-weight (50 cases) and normal-weight groups (61 cases) based on BMI. All of the children received ICS for one year. Pulmonary functions were evaluated before and after treatment. Large airway function includes forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%). Small airway function includes maximal expiratory flow 25 (MEF25%) and maximal expiratory flow 50 (MEF50%).</p><p><b>RESULTS</b>The bronchial provocation test before treatment showed that the decline rate of pulmonary function (FVC%, FEV1%, MEF25% and MEF50%) in the obese group was higher than the normal-weight group after methacholine inhalation. After salbutamol inhalation, the improvement rate of the large airway (FVC%) and small airway (MEF25% and MEF50%) functions in the obese group was lower than the normal-weight group, and the improvement rate of small airway (MEF25% and MEF50%) function in the over-weight group was lower than in the normal-weight group. After treatment with ICS for one year, large airway function (FVC% and FEV1%) in the normal-weight group was higher than pre-treatment, however only FVC% in the normal-weight and obese groups was higher than pre-treatment. There was no significant difference in small airway function before and after treatment in all three groups.</p><p><b>CONCLUSIONS</b>Obesity can increase the sensitivity to methacholine and restrain the sensitivity to tosalbutamol in children with asthma. ICS can improve the large airway function in asthmatic children with normal body weight, but has no effect on small airway function. Obesity can restrain the effect of ICS on asthmatic children.</p>