ABSTRACT
Objective:To examine chromosomes of a total of 10 857 people who asked for prenatal genetic counseling in our hospital from February 1994 to July 2018. The important diagnostic reference index for the clinical diagnosis, screening for genetic abnormality and carrying out appropriate guidance have been done for them to adopt appropriate prenatal strategies and realize a first-degree prevention and control of birth defects.Methods:Routine G banding analysis was performed on genetic counselors. C banding, N banding analysis and whole genome sequencing were performed according to abnormal karyotypes.Results:The chromosome aberration karyotype 46, X, inv(Y)(p11.2q11.2) pat/45, X pat, number: 3 574 was found and reported for the first time across the globe; Besides, this aberrant chromosome karyotype experienced stable inheritance of two generations in 8 adult males of three families.Conclusions:The adult males in three families have normal phenotype and they can still have normal fertility. Among those people, no pathogenic gene has been detected and no genetic material has lost or increased. The same aberration karyotype has been found in all 8 adult males of two generations. The ratio of these two generations’ karyotype is one out of ten thousand. As a rare genetic polymorphism, the abnormal karyotype can be regarded as an evolutionary marker, and play a unique role in paternity testing. In addition, the inverted Y chromosome can also be used to study the route of population migration. As a marker of genetic relationship, it may provide a method to study population genetics and historical geography.
ABSTRACT
Objective:Torque teno virus(TTV), are reported in a wide range of mammals. In this study, we sequenced and analyzed the complete genome of a genetic variant of Rodent TTV, RoTTV3-HMU1 (Hainan Medical University). The virus was harbored by a Rattus norvegicus in the residential areas of Hainan Island, China.Methods:Torque Teno virus (TTV) was found widely distributed throughout the world infecting an extensively wide range of mammals .We extracted the viral DNA from a Rattus norvegicus liver which was caught from the residential areas of Hainan Island. Purifying the amplicons in the range of 250-500 bp. Then Five hundred nanograms DNA was subjected to high-throughput sequencing. The contigs were compared with the NCBI nucleiotide database, designed the primers to cover the genome by PCR amplification and amplicons of each PCR which have been cloned and sequenced. Finally the genome was annotated by using NCBI ORF finder and FGENESV0. Phylogenetic analysis was implemented by the neighbor-joining method in the MEGA6 software package.Results:We sequenced the complete genome of a genetic variant of Rodent TTV, RoTTV3- HMU1. The genomic sequence of RoTTV3-HMU1 has been deposited in GenBank under accession number MF688246.1. The complete genome of RoTTV3-HMU1 is 2 570 nucleotides (nt) in length with a G+C content of 46.93%. RoTTV3-HMU1 encoded 3 unidirectional overlapping open reading frames (ORF). Sequence analysis indicated that the genome of RoTTV3-HMU1 virus was most closely related to RN_2_15 (GenBank accession no. KM668486.1). Phylogenetic analysis based on both ORF1 and the total genome sequence placed RoTTV3-HMU1 in to the clad RoTTV3 of the RoTTV.Conclusions:Hainan Island faces mainland across the sea, however, the same genotype of RoTTV was identified in both Hainan Island and the other part of China. The detection of RoTTV3-HMU1 contributed to a better understanding about the origin and evolution of RoTTV.