OBJECTIVETo explore the genetic cause of a female patient with severe mental retardation and a history of adverse pregnancy.

METHODSThe patient was subjected to G-banded chromosome analysis and single nucleotide polymorphism array (SNP-array) assaying. The correlation between genomic variations and the phenotype was explored.

RESULTSThe patient was found to have a complex chromosome rearrangement involving 5 chromosomes. The karyotypes of her parents were both normal. SNP-array assay has identified a 1.6 Mb microdeletion at chromosome 15q21.3 which involved 15 RefSeq genes and a 0.5 Mb microdeletion at 5q21.1 which involved one RefSeq gene.

CONCLUSIONThe microdeletions, which involved TCF12, ADMA10 and AQP9 genes, probably underlie the mental retardation shown by the patient.

Adult ; Chromosome Banding ; methods ; Chromosome Deletion ; Chromosomes ; genetics ; Female ; Genetic Testing ; methods ; Humans ; Intellectual Disability ; genetics ; Karyotype

OBJECTIVE To analyze a neonate with multiple malformations and to correlate its genotype with phenotype. METHODS The karotypes of the child and her parents were subjected to G-banding chromosome analysis, and array comparative genomic hybridization (array-CGH) was used for fine mapping of the aberrant region. RESULTS The karyotype of the child was ascertained as 46,XX,del(18)(p11.2). Array CGH has identified a 9.8 Mb deletion at 18p11.32-p11.22. The patient has presented features such as holoprosencephaly, choanal atresia, heart defect, and craniofacial dysmorphisms. CONCLUSION The de novo 18p deletion probably underlies the main clinical manifestations of the child.
Abnormalities, Multiple ; genetics ; Chromosome Banding ; Chromosome Deletion ; Chromosomes, Human, Pair 18 ; Female ; Humans ; Infant, Newborn ; Phenotype

OBJECTIVETo explore the genetic cause for a child with developmental delay.

METHODSThe karotypes of the child and her parents were analyzed with G-banding analysis. Their genome DNA was analyzed with low-coverage massively parallel copy number variation sequencing (CNV-seq) and verified by single nucleotide polymorphism array (SNP-array).

RESULTSThe karyotype of the child was ascertained as 46,XX,r(15)(p13q26.3), while both parents showed a normal karyotype. CNV-seq and SNP-array have identified a de novo 15q26.2-q26.3 deletion in the child with a size of approximately 3.60 Mb.

CONCLUSIONThe abnormal phenotype of the patient carrying the ring chromosome 15 may be attributed to the presence of the 15q26.2-q26.3 microdeletion. The deletion and haploinsufficiency of the IGF1R gene probably underlie the main clinical features of the patient.

Child, Preschool ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; genetics ; DNA Copy Number Variations ; Female ; Humans ; Karyotyping ; Mosaicism ; Ring Chromosomes ; Sequence Deletion

Stem cells are a class of undifferentiated cells with high self⁃renewal and rapid proliferative capabilities. Undercertain conditions, stem cells can induce differentiation into other tissue cells of the human body, such as skeletal muscle cells, cardiomyocytes, osteoblasts, and nerve⁃like cells. In recent years, with the development of tissue engineer⁃ ing and regenerative medicine, stem cells have been extensively used in various fields of regenerative medicine as opti⁃ mal seeded cells; however, there are still some problems, such as the decreased cell survival rate and regenerative ca⁃ pacity after transplantation, immune rejection, and ethical supervision. Therefore, it is difficult to universally and safely use stem cell banks for regeneration applications. The paracrine effect of stem cells has been extensively studied since its discovery. Increasing evidence supports the view that stem cells act in paracrine manner, and the secretion of exo⁃ somes plays a vital role in their biological functions. Exosomes are nanoscale extracellular vesicles containing biological⁃ ly active molecules such as RNA and proteins; they possess similar functions to stem cells and play important roles in cell communication, immune response, and repair of tissue damage. At present, clinical studies on stem cell exosomes in tissue engineering and regenerative medicine have also been carried out in the fields of bone and cartilage repair, nerve tissue regeneration, liver tissue regeneration, skeletal muscle tissue engineering, vascular regeneration, taste bud repair, tooth regeneration, etc. In this paper, the composition, formation, release and identification of exosomes are intro⁃ duced in detail. The research status of exosomes from different stem cell sources in tissue engineering and regenerative medicine is described, and their broad application prospects are discussed.