OBJECTIVETo analyze the clinical manifestations and mutation of MYH9 gene in a large Chinese family affected with MYH9-related thrombocytopenia.

METHODSAfter informed consent was obtained; clinical examination and history investigation was performed on 29 members of the family. DNA was extracted using a standard method, then exons 1 to 40 and their corresponding exon-intron junctions of the MYH9 gene were amplified with PCR and subjected to Sanger sequencing. The results were compared to reference sequence from the University of California, Santa Cruz (UCSC) to screen the mutation. PCR and Sanger sequencing was performed on genome DNA of all family members to confirm the identified mutation.

RESULTSThe clinical manifestations of family members were prominently heterogeneous. Four affected members showed hearing loss or deafness, two affected members showed nephritis or kidney failure, and other affected members was only characterized by mild bleeding or with no obvious symptoms. A heterozygous missense mutation c.4270G>A (p.Aspl841Asn) in exon 30 of the MYH9 gene was identified in all affected members from this family, which also co-segregated with the phenotype.

CONCLUSIONA missense mutation c.4270G>A (p.Aspl841Asn) within the exon 30 of the MYH9 gene was identified to be associated with MYH9-related thrombocytopenia in a Chinese family.

Amino Acid Sequence ; Asian Continental Ancestry Group ; genetics ; China ; DNA Mutational Analysis ; Exons ; genetics ; Family Health ; Female ; Genetic Predisposition to Disease ; ethnology ; genetics ; Heterozygote ; Humans ; Male ; Molecular Motor Proteins ; genetics ; Mutation, Missense ; Myosin Heavy Chains ; genetics ; Pedigree ; Sequence Homology, Amino Acid ; Thrombocytopenia ; ethnology ; genetics

Objective: To explore the genetic basis of a pedigree affected with hereditary spherocytosis. Methods: Peripheral blood samples were collected from 17 members of the pedigree. Genomic DNA of the proband was subjected to next generation sequencing. Candidate variant was validated by co-segregation analysis. pCAS2^{c.5798+ 1G} and pCAS2^{c.5798+ 1A} plasmids were constructed by homologous recombination and transfected into 293T cells. Reverse transcription PCR, TA cloning and Sanger sequencing were used to analyze the effect of candidate variant on splicing. Meanwhile, peripheral blood RNAs were extracted to analyze the effect of candidate variant on splicing in vivo. Results: The proband was found to carry a c. 5798+ 1G>A variant of the SPTB gene. The variant has co-segregated with the phenotype in the pedigree. In vitro and in vivo splicing experiments confirmed that the mutation has significantly affected the splicing, resulting in shift of reading frame and produced a premature termination codon. Conclusion The novel c. 5798+ 1G>A variant of the SPTB gene probably underlies the pathogenesis of hereditary spherocytosis in this pedigree.

Objective:To compare the difference between breast bracket combined with polyurethane foam and single polyurethane foam in the accuracy of immobilization, providing a better immobilization for breast cancer radiotherapy.Methods:Fifty breast cancer patients who received radiotherapy in Sun Yat-sen University Cancer Center from March 2021 to July 2021 were selected. Among them, 25 patients were immobilized with polyurethane foam (foam group), and the other 25 patients were immobilized with polyurethane foam combined with breast bracket (combination group). All patients were scanned by CBCT once a week to obtain setup errors in the SI, LR and AP directions for t-test. The formula M PTV=2.5 Σ+0.7 σ was used to calculate the margin of the planning target volume(M PTV). Results:The setup errors in the foam group were SI (2.0±3.26) mm, LR (0.88±2.76) mm, AP (1.22±3.55) mm, Rtn -0.24°±0.85°, Pitch 0.16°±1.11°, Roll -0.32°±1.05°, and the M PTV were 6.75 mm, 8.46 mm and 8.73 mm, respectively. The setup errors in the combination group were SI (1.0±3.01) mm, LR (0.62±2.74) mm, AP (1.82±3.21) mm, Rtn 0.64°±0.59°, Pitch 0.71°±1.22°, Roll 0.29°±0.73°, and the M PTV were 6.35 mm, 7.47 mm, and 7.61 mm, respectively. After comparing the setup errors in the three-dimensional directions between two groups, the t value of LR, SI, AP and Rtn, Pitch, Roll was -4.304, -2.681, 1.384, and -9.457, -3.683, -5.323, respectively. And the differences in the LR, SI, Rtn, Pitch and Roll directions were statistically significant (all P<0.05). Conclusions:The immobilization effect of polyurethane foam combined with breast bracket is better and the M PTV is also smaller than those of polyurethane foam alone. Therefore, it is recommended to use polyurethane foam combined with breast bracket for immobilization in breast cancer radiotherapy.

Objective:To investigate the association between prenatal genotype and phenotype of 16p13.11 microdeletion syndrome, aiming to provide a reference for prenatal diagnosis and genetic counseling.Methods:This retrospective study analyzed the results of comparative genomic hybridization microarray and low-coverage whole genome sequencing performed on 4 230 pregnant women in the Henan Provincial People's Hospital from July 2018 to July 2021. Indications for prenatal diagnosis, pedigree information and pregnancy outcomes of 17 fetuses with 16p13.11 microdeletion were described.Results:Prenatal diagnostic indications in the 17 fetuses were ultrasound abnormalities in five cases (increased nuchal translucency in four and cerebral ventriculomegaly with 10.7 mm in one), inter-twin weight discordance over 20% in one case, high risk in five cases and marginal risk in one in trisomy-21 serum screening, advanced maternal age in three cases (one with echogenic intracardiac focus in the left ventricle and two with normal ultrasound images) and adverse pregnancy history in two cases with normal ultrasound images. Pedigree verification that performed on 12 cases revealed that five were caused by de novo mutations and seven were inherited from their parents. The follow-up results showed that five cases were terminated, two lost to follow-up and 10 born alive (inheritance patterns were de novo mutations in three cases, parental inheritance in six and unknown pattern in one). These 10 infants were followed up from age 7 months to 3 years and 2 months and the results showed that one case was born with choroid plexus cyst of the left ventricle and presented instability of gait at 1 year and 3 months; one was a premature infant with 33 gestational weeks whose parents reported his language ability was not well at 2 years and 1 month old but without other abnormalities; one case had low muscle tone and was unable to keep head upright at 3 months who recovered at 5 months old after rehabilitation treatment according to the parents' report; all seven parents in the remaining seven cases reported no abnormalities. Conclusions:There was no specific prenatal diagnostic indication for 16p13.11 microdeletion syndrome. Genetic tracing, pregnancy outcome analysis and follow-up surveillance would provide reference for genetic counseling of 16p13.11 microdeletion syndrome.

A change in the metabolic flux of glucose from mitochondrial oxidative phosphorylation (OXPHOS) to aerobic glycolysis is regarded as one hallmark of cancer. However, the mechanisms underlying the metabolic switch between aerobic glycolysis and OXPHOS are unclear. Here we show that the M2 isoform of pyruvate kinase (PKM2), one of the rate-limiting enzymes in glycolysis, interacts with mitofusin 2 (MFN2), a key regulator of mitochondrial fusion, to promote mitochondrial fusion and OXPHOS, and attenuate glycolysis. mTOR increases the PKM2:MFN2 interaction by phosphorylating MFN2 and thereby modulates the effect of PKM2:MFN2 on glycolysis, mitochondrial fusion and OXPHOS. Thus, an mTOR-MFN2-PKM2 signaling axis couples glycolysis and OXPHOS to modulate cancer cell growth.