Objective:To analyze the applicability and feasibility of a cell-free DNA barcode-enabled single-molecule test (cfBEST) in non-invasive prenatal diagnosis of phenylketonuria.Methods:This study recruited four pregnant women who were prenatally diagnosed as heterozygous carriers of hot spot mutations in the PAH gene from pedigrees with phenylketonuria at the First Affiliated Hospital of Zhengzhou University from July to September 2019. The frequency of mutations in maternal plasma cell-free DNA and the fetuses' genotypes were analyzed by cfBEST. Nested polymerase chain reaction primers were designed to amplify the mutation sites in each pedigree. The results of cfBEST were compared with those of invasive prenatal diagnosis. Descriptive analysis was used for data analysis. Results:In pedigree 1, the frequency of c.603T>G and c.842+2T>A mutations in maternal plasma cell-free DNA were 48.40% (291/601) and 9.70% (61/628), which was detected by cfBEST. The fetus was diagnosed with phenylketonuria with two heterozygous mutations. In pedigree 2, the frequency of c.1238G>C and c.842+2T>A mutations in maternal plasma cell-free DNA was 43.70% (786/1 798) and 0% (0/1 550), respectively. Both mutations were wild-type, and the fetus was neither phenylketonuria nor a carrier. In pedigree 3, the frequency of c.1045T>G and c.728G>A mutations in maternal plasma cell-free DNA was 44.00% (930/2 112) and 0% (0/705), respectively, suggesting that both mutations in the fetus were wild-type, and the fetus was neither phenylketonuria nor a carrier. In pedigree 4, the frequency of c.755G>A and c.728G>A mutations were 45.40% (743/1 637) and 4.50% (28/849), respectively, which indicated that the former was wild-type, and the latter was heterozygous; namely the fetus was a carrier of phenylketonuria. The results of cfBEST were consistent with those of invasive prenatal diagnosis. Three pedigrees (Pedigree 2, 3 and 4) continued the pregnancy to full-term, and the phenylalanine levels in the neonates were all below 120 μmol/L. No abnormalities were reported in those three infants during follow-ups at one, three, and six months after birth.Conclusions:The cfBEST could be used for non-invasive prenatal diagnosis of phenylketonuria caused by PAH gene mutation, but further studies with a larger sample size are needed.

OBJECTIVE: To determine the spectrum of pathological genetic variants among 405 Chinese pedigrees affected with oculocutaneous albinism (OCA). METHODS: A total of 405 OCA patients were collected. High-throughput sequencing (The panel included TYR, OCA2, TYRP1 and SLC45A2 genes), Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) were used to analyze the genetic variants and patterns of each subtype. RESULTS: The overall detection rate of genetic variants was 79.9% (647/810), and the variants included missense variants (57.3%, 371/647), frameshift variants (22.9%, 148/647), nonsense variants (13.9%, 90/647), splicing variants (5.6%, 36/647), and microdeletions (0.3%, 2/647). Thirty-six novel variants were detected. Of the 405 patients, 306 have carried 2 variant alleles (75.6%, 306/405), 35 carried 1 variant alleles (8.6%, 35/405), while no variant was detected in 64 patients. Among the 306 genetically diagnosed OCA patients, OCA1 was the most common form (74.5%, 228/306), compared with OCA2 (15.0%, 46/306), OCA3 (0.7%, 2/306) and OCA4 (9.8%, 30/306), respectively. One patient was found to harbor homozygous c.1262-4_c.1262-3insTAGA variant of the TYRP1 gene. Another patient was found to carry compound heterozygous variants of c.1214C>A (p.T405N) and c.1338delinsCG(p.V447Gfs*19) of the TYRP1 gene. CONCLUSION High-throughput sequencing in combination with Sanger sequencing and MLPA can effectively detect genetic variants associated with OCA. Above finding has expanded variant spectrum of OCA, which can facilitate genetic and prenatal diagnosis of this disease in China.

OBJECTIVE: To explore the genetic basis for a child featuring Chediak-Higashi syndrome (CHS). METHODS: Clinical manifestations and results of auxiliary examination of the proband were analyzed. The proband was subjected to whole exome sequencing, and the results were verified by Sanger sequencing. Correlation between the genotype and clinical phenotype was analyzed. RESULTS: The proband showed partial skin albinism, recurrent respiratory infection and other immune deficiencies. Genetic testing showed that he has harbored c.2437C>T (p.Arg813*) and c.6077dupA (p.Tyr2026fs) (NM_000081) compound heterozygous variants of the LYST gene, for which his parents were both carriers. Neither variant was reported previously. HEAT repeats domain was frequently associated with more severe phenotype of CHS (81.6%), whilst no variant has been found in the PH_BEACH domain. CONCLUSION This study has enriched the spectrum of LYST gene variants associated with CHS and enabled clinical diagnosis, prenatal diagnosis and prognostic evaluation for the child.
Male ; Humans ; Chediak-Higashi Syndrome/genetics* ; Vesicular Transport Proteins/genetics* ; Heterozygote ; Genetic Testing ; China

17β-estradiol (E2) treatment of cells results in an upregulation of SIRT1 and a down-regulation of PPARγ. The decrease in PPARγ expression is mediated by increased degradation of PPARγ. Here we report that PPARγ is ubiquitinated by HECT E3 ubiquitin ligase NEDD4-1 and degraded, along with PPARγ, in response to E2 stimulation. The PPARγ interacts with ubiquitin ligase NEDD4-1 through a conserved PPXY-WW binding motif. The WW3 domain in NEDD4-1 is critical for binding to PPARΓ. NEDD4-1 overexpression leads to PPARγ ubiquitination and reduced expression of PPARγ. Conversely, knockdown of NEDD4-1 by specific siRNAs abolishes PPARΓ ubiquitination. These data indicate that NEDD4-1 is the E3 ubiquitin ligase responsible for PPARγ ubiquitination. Here, we show that NEDD4-1 delays cellular senescence by degrading PPARΓ expression. Taken together, our data show that E2 could upregulate SIRT1 expression via promoting the PPARΓ ubiquitination-proteasome degradation pathway to delay the process of cell senescence.
Amino Acid Motifs ; Animals ; Cellular Senescence ; Down-Regulation ; drug effects ; Endosomal Sorting Complexes Required for Transport ; antagonists & inhibitors ; genetics ; metabolism ; Estradiol ; pharmacology ; Female ; HeLa Cells ; Humans ; Mice ; Mice, Inbred BALB C ; Nedd4 Ubiquitin Protein Ligases ; PPAR gamma ; genetics ; metabolism ; Proteasome Endopeptidase Complex ; metabolism ; Protein Structure, Tertiary ; RNA Interference ; RNA, Small Interfering ; metabolism ; Sirtuin 1 ; genetics ; metabolism ; Ubiquitin ; metabolism ; Ubiquitin-Protein Ligases ; antagonists & inhibitors ; genetics ; metabolism ; Ubiquitination ; drug effects ; Up-Regulation ; drug effects

OBJECTIVE: To describe the clinical and genetic characteristics of a child with 14q12q13.1 deletion involving the FOXG1 gene. METHODS: Clinical manifestation of the child was analyzed. Peripheral blood sample of the patient was subjected to chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) analysis. RESULTS: The male infant has developed feeding difficulty, poor sucking, lower limb tremor, and frontal bruising 8 days after birth. Magnetic resonance imaging revealed significant enlargement of bilateral ventricles and corpus callosum dysplasia. Chromosomal analysis revealed a karyotype of 46,XY,del(14)(q12q13.1), and SNP-array confirmed that there was a 9.6 Mb deletion in 14q11.2q13.1, which encompassed the FOXG1 gene. CONCLUSION For patients with brain development abnormalities, dyskinesia, cognitive impairment, speech disorder and other manifestations, copy number variation of the FOXG1 gene should be excluded. SNP-array should be carried out as early as possible to attain the diagnosis.
Child ; Chromosome Deletion ; DNA Copy Number Variations ; Forkhead Transcription Factors/genetics* ; Heterozygote ; Humans ; Infant ; Karyotyping ; Male ; Nerve Tissue Proteins/genetics* ; Polymorphism, Single Nucleotide

OBJECTIVE: To delineate chromosomal aberration caused by structural chromosomal abnormalities with bionano optical mapping. METHODS: Chromosomal karyotyping, bionano optical mapping and copy number variation sequencing (CNV-seq) were used to delineate the chromosomal aberration carried by a patient. RESULTS: The patient was found to have an anomalous chromosome 16 by karyotyping analysis, which was verified by bionano optical mapping and CNV-seq as loss of heterozygosity at 16p11.2-p12.2. CONCLUSION Bionano optical mapping has provided a novel tool for the detection and diagnosis of structural chromosomal aberrations.

We report the use of droplet digital polymerase chain reaction (ddPCR) in non-invasive prenatal test fetal Charcot-Marie-Tooth disease (CMT) caused by MFN2 gene mutation. The proband, namely the husband, was found with heterozygous mutation of c.919A>G(p.K307E) in the MFN2 gene, which was diagnosed as CMT type 2A2A at a local hospital. The proband's wife underwent genetic counseling after conception at the First Affiliated Hospital of Zhengzhou University. Peripheral blood obtained from the pregnant woman was analyzed by ddPCR at eight gestational weeks, which found the fetus to carry a paternal pathogenic gene mutation. Sanger sequencing for the chorionic sample at 11 gestational weeks further verified that the fetus was a c.919G>A(p.K307E) heterozygous mutation carrier, the same as the proband. ddPCR could be applied to cell-free fetal DNA to detect the paternal pathogenic gene mutation in the non-invasive prenatal test.

OBJECTIVE: To explore the clinical effect of expanded non-invasive prenatal testing (NIPT-plus) for prenatal screening. METHODS: The screening result, prenatal diagnosis and pregnancy outcome of 3700 pregnant women who volunteered NIPT-plus screening at our center from September 2018 to December 2019 were reviewed. RESULTS: Among the 3700 pregnant women, 74(2.0%) were scored positive for clinically significant fetal chromosomal abnormalities and underwent NIPT-plus screening. Sixty three women with a high risk underwent invasive prenatal diagnosis, among whom 19 were diagnosed, which yielded a positive predictive value (PPVs) of 30.2% (19/63). Statistical analysis showed that NIPT-plus has higher PPVs for common aneuploidies and low-to-medium PPVs for sex chromosome aneuploidies and microdeletion/microduplication syndromes. CONCLUSION As a screening technique, NIPT-plus has broader applications compared with conventional techniques, and has reference value for clinicians and pregnant women during pregnancy.
Aneuploidy ; Chromosome Aberrations ; Female ; Humans ; Pregnancy ; Pregnancy Outcome ; Prenatal Diagnosis ; Sex Chromosome Aberrations

OBJECTIVE: To carry out genetic testing and prenatal diagnosis for a Chinese couple whom had conceived two fetuses featuring multiple malformations including polycystic kidney, polydactyly and encephalocele. METHODS: Following elective abortion, the fetus from the second pregnancy was subjected to whole exome sequencing. Suspected pathogenic variants were verified by Sanger sequencing of the fetus and its parents. RESULTS: The fetus was found to harbor compound heterozygous variants of the CEP290 gene, namely c.2743G>T (p.E915X) and c.2587-2A>T, which were respectively inherited from its father and mother. The same variants were not detected among 100 healthy controls nor reported previously. Bioinformatic analysis suggested both variants to be deleterious. The fetus was diagnosed with Meckel-Gruber syndrome. Prenatal diagnosis for the couple during their next pregnancy suggested that the fetus did not carry the above pathogenic variants. CONCLUSION The compound heterozygous variants of the CEP290 gene probably underlay the pathogenesis of Meckel-Gruber syndrome in the second fetus. Above finding has provided a basis for genetic counseling and prenatal diagnosis for the couple, and also enriched the mutational spectrum of the CEP290 gene.
China ; Ciliary Motility Disorders ; Encephalocele/genetics* ; Female ; Genetic Testing ; Humans ; Pedigree ; Polycystic Kidney Diseases/genetics* ; Pregnancy ; Prenatal Diagnosis ; Retinitis Pigmentosa

OBJECTIVE: To explore the clinical characteristics and molecular pathogenesis of a child with autosomal dominant polycystic kidney disease (ARPKD). METHODS: Prenatal ultrasound, clinical feature and family history of the child were analyzed. Whole exome sequencing was carried out for the child. Candidate variants were verified by Sanger sequencing. RESULTS: The child has featured premature birth with very low weight, neonatal respiratory distress, metabolic acidosis, and congenital nephrotic syndrome. Gene sequencing revealed that he has harbored compound heterozygous variants of the PKHD1 gene (NM_138694), including c.3885T>A (p.Tyr1295*) in exon 32 and c.7812_7816dupTGATA (p.Thr2606Metfs*63) in exon 49, which were respectively inherited from his mother and father. CONCLUSION The compound heterozygous variants of the PKHD1 gene probably underlay the disease in this child.
Child ; Exons ; Female ; Genetic Testing ; Humans ; Infant, Newborn ; Male ; Mutation ; Polycystic Kidney, Autosomal Recessive/genetics* ; Pregnancy ; Receptors, Cell Surface/genetics*