Objective To observe the degeneration of Brugia malayi in Meriones unguiculatus model. Methods Microfilaria of Brugia malayi derived from Meriones unguiculatus was used to infect Anopheles sinensis . Infective stage larvae (L 3) from mosquito vector were collected and inoculated into abdomen of Meriones unguiculatus. Successive 33 generations of the parasite in the rodent model have been observed. Results Since 1974 when the animal model was established, the parasite has lasted for 33 generations, the positive rate of Meriones unguiculatus with microfilaria gradually reduced from 80% of the 28th generation to 16% of the 32nd generation and finally to 0 at the 33rd generation. Conclusion It became difficult for the larvae of Brugia malayi to develop and/or reproduce in the animal model after multiple inoculations for generations.

Objective To establish a specific, sensitive and simple assay for the detection of Brugia malayi larva in Anopheles sinensis .Methods Using a new DNA purification technique (Microcon 100) and two pairs of oligonucleotide primers (p1, p2 and p3,p4) suitable for detecting B malayi in seven areas in our country, the mosquito vectors infected by B malayi were detected by polymerase chain reaction(PCR).Results This PCR method could amplify separately a 322 basepair(bp) and a 155 bp DNA fragment and detect as few as 1/64 of one L 1 in 1 mosquito,the detectable limit was nearly 4 pg DNA of filarial larvae, and it could also detect 1 infected mosquito with one L 3 of B malayi in pools of up to 200 mosquitoes. In contrast,no such specific 322 bp or 155 bp DNA band was detected in Dilofilaria immitis and normal mosquito.Conclusion This PCR techique established for supervision of mosquito vector in B malayi endemic areas is specific,sensitive,and simple.

Objective: To identify potential variant in a child diagnosed as infantile neuroaxonal dystrophy. Methods: Genomic DNA was extracted from peripheral blood samples from the patient and his parents and subjected to next generation sequencing. Suspected variant was verified by PCR and Sanger sequencing. Pathogenicity of the mutation was predicted by using bioinformatic software including SIFT and PolyPhen-2. Results: The child was found to carry compound heterozygous variations c. 668C>A (p.Pro223Gln) and c. 2266C>T (p.Gln756Ter) of the PLA2G6 gene, which were respectively inherited from his father and mother. c. 2266C>T has changed codon 756 (glutamine) into a stop codon, resulting premature termination of peptide chain synthesis. c. 2266C>T has not been reported previously and was predicted to be harmful. Conclusion The compound variants of c. 668C>A (p.Pro223Gln) and c. 2266C>T (p.Gln756Ter) of the PLA2G6 gene probably underlies the disease in the child. Above finding has enriched the variant spectrum of the PLA2G6 gene.

Objective: To analyze variations of TYR and P genes among 14 patients with clinically diagnosed oculocutaneous albinism. Methods: Potential variations of the TYR and P genes were detected by Sanger sequencing. Novel variations were predicted with bioinformatics software including SIFT and PolyPhen-2. Results: No variation was found in the TYR gene, while 9 types of variations were found in the P gene among the 14 patients, which included c. 803-3C>G (7/26), c. 1327G>A (p.Val443Ile) (5/26), c. 632C>T (p.Pro211Leu) (4/26), c. 1832T>C (p.Leu611Pro) (3/26), c. 1349C>A (p.Thr450Lys) (2/26), c. 2363C>T (p.Ser788Leu) (2/26), c. 2228C>T (p.Pro743Leu) (1/26), c. 1525A>G(p.Thr509Ala) (1/26), and c. 1349C>T(p.Thr450Met) (1/26). Only 1 heterozygous variation was detected in 2 families. c. 2363C>T (p.Ser788Leu), c. 1832T>C (p.Leu611Pro) and c. 1525A>G (p.Thr509Ala) were not reported previously and predicted as "harmful" to the protein function. Conclusion The main type of ocular albinism is oculocutaneous albinism type Ⅱ in Liuzhou region, where the most common variations of the P gene were c. 803-3C>G and c. 1327G>A (p.Val443Ile). Above finding has enriched the variation spectrum of the P gene.

OBJECTIVE: To carry out mutation analysis and prenatal diagnosis for a family affected with primary carnitine deficiency. METHODS: Genomic DNA of the proband was extracted from peripheral blood sample 10 days after birth. The 10 exons and intron/exon boundaries of the SLC22A5 gene were subjected to PCR amplification and Sanger sequencing. The proband's mother was pregnant again two years after his birth. Fetal DNA was extracted from amniocytes and subjected to PCR and Sanger sequencing. RESULTS: Tandem mass spectrometric analysis of the proband revealed low level of plasma-free carnitine whilst organic acids in urine was normal. Compound heterozygous SLC22A5 mutations c.1195C>T (inherited from his father) and c.517delC (inherited from his mother) were detected in the proband. Prenatal diagnosis has detected no mutation in the fetus. The plasma-free carnitine was normal after birth. CONCLUSION Appropriate genetic testing and prenatal diagnosis can prevent further child with carnitine deficiency. The identification of c.517delC, a novel mutation, enriched the spectrum of SLC22A5 mutations.
Cardiomyopathies ; genetics ; Carnitine ; deficiency ; genetics ; Child, Preschool ; DNA Mutational Analysis ; Female ; Humans ; Hyperammonemia ; genetics ; Muscular Diseases ; genetics ; Mutation ; Pregnancy ; Prenatal Diagnosis ; Solute Carrier Family 22 Member 5 ; genetics

OBJECTIVE: To detect variants of IVD gene among 4 neonates with suspected isovalerate acidemia in order to provide a guidance for clinical treatment. METHODS: 111 986 newborns and 7461 hospitalized children with suspected metabolic disorders were screened for acyl carnitine by tandem mass spectrometry. Those showing a significant increase in serum isovaleryl carnitine (C5) were analyzed for urinary organic acid and variants of the IVD gene. RESULTS: Four cases of isovalerate acidemia were detected, which included 2 asymptomatic newborns (0.018‰, 2/111 986) and 2 children suspected for metabolic genetic diseases (0.268‰, 2/7461). The formers had no obvious clinical symptoms. Analysis of acyl carnitine has suggested a significant increase in C5, and urinary organic acid analysis has shown an increase in isovaleryl glycine and 3-hydroxyisovalerate. Laboratory tests of the two hospitalized children revealed high blood ammonia, hyperglycemia, decreased red blood cells, white blood cells, platelets and metabolic acidosis. The main clinical manifestations have included sweaty foot-like odor, feeding difficulty, confusion, drowsiness, and coma. Eight variants (5 types) were detected, which included c.158G>A (p.Arg53His), c.214G>A (p.Asp72Asn), c.548C>T (p.Ala183Val), c.757A>G (p.Thr253Ala) and 1208A>G (p.Tyr403Cys). Among these, c.548C>T and c.757A>G were unreported previously. None of the variants was detected by next generation sequencing of 2095 healthy newborns, and all variants were predicted to be likely pathogenic based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION The incidence of isovalerate acidemia in Liuzhou area is quite high. Screening of metabolic genetic diseases is therefore recommended for newborns with abnormal metabolism. The discovery of novel variants has enriched the mutational spectrum of the IVD gene.
Infant, Newborn ; Child ; Humans ; Acidosis ; Carnitine ; Erythrocytes ; High-Throughput Nucleotide Sequencing

Objective:To explore the genetic basis for a child featuring global developmental delay and epilepsy.Methods:A child who had presented at Guangzhou Women and Children′s Medical Center Liuzhou Hospital on February 19, 2023 was selected as the study subject. Clinical data of the child was collected. The child was subjected to whole exome sequencing, and candidate variant was validated by Sanger sequencing and bioinformatic analysis.Results:The child, an 8-month-old girl, had manifested with global developmental delay, epilepsy, and hyperlactacidemia. Cranial MRI revealed diverse hypomyelinating leukodystrophies. Electroencephalogram showed slow background activities. Genetic testing revealed that she has harbored a homozygous variant of the SLC25A12 gene, namely c. 115T>G (p.Phe39Val), for which both of her parents were heterozygous carriers. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was predicted to be of uncertain significance (PM2_Supporting+ PM3_Supporting+ PP3_Moderate+ PP4_Moderate). I-Mutant v3.0 software predicted that the variant may affect the stability of protein product. Conclusion:The homozygous c. 115T>G (p.Phe39Val) variant of the SLC25A12 gene probably underlay the pathogenesis of the disease in this child.