Y Chromosome Research Articles

Neuropeptide Y Y2 Receptors in Sensory Neurons Tonically Suppress Nociception and Itch but Facilitate Postsurgical and Neuropathic Pain Hypersensitivity.

Neuropeptide Y (NPY) Y2 receptor (Y2) antagonist BIIE0246 can both inhibit and facilitate nociception. The authors hypothesized that Y2 function depends on inflammation or nerve injury status. The authors implemented a battery of behavioral tests in mice of both sexes that received (1) no injury; (2) an incision model of postoperative pain; (3) a spared nerve injury model of neuropathic pain; and (4) a latent sensitization model of chronic postsurgical pain. In addition to Y2 gene expression assays, spinal Y2 G-protein coupling was studied with guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPγS) binding assays. The authors report that intrathecal BIIE0246 increased mechanical and cold hypersensitivity, produced behavioral signs of spontaneous nociception and itch, and produced conditioned place aversion and preference in normal, uninjured mice. BIIE0246 did not change heat hypersensitivity or motor coordination. Conditional (sensory neuron-specific) Y2 deletion prevented BIIE0246-induced mechanical and cold hypersensitivity, nocifensive behaviors, and aversion. Both conditional deletion and pharmacologic blockade of Y2 reduced mechanical and thermal hypersensitivity after incision or nerve injury. SNI did not change the sensitivity of Y2 G-protein coupling with the Y2 agonist peptide YY (3-36) (PYY3-36), but increased the population of Y2 that effectively coupled G-proteins. Intrathecal PYY3-36 failed to reduce spared nerve injury- or incision-induced hypersensitivity in C57BL/6N mice. Incision did not change Npy2r gene expression in dorsal root ganglion. The authors conclude that Y2 at central terminals of primary afferent neurons provides tonic inhibition of mechanical and cold nociception and itch. This switches to the promotion of mechanical and thermal hyperalgesia in models of acute and chronic postsurgical and neuropathic pain, perhaps due to an increase in the population of Y2 that effectively couples to G-proteins. These results support the development of Y2 antagonists for the treatment of chronic postsurgical and neuropathic pain.

Ribosomal DNA Instability as a Potential Cause of Karyotype Evolution.

Karyotype refers to the configuration of the genome into a set of chromosomes. The karyotype difference between species is expected to impede various biological processes, such as chromosome segregation and meiotic chromosome pairing, potentially contributing to incompatibility. Karyotypes can rapidly change between closely related species and even among populations of the same species. However, the forces driving karyotype evolution are poorly understood. Here we describe a unique karyotype of a Drosophila melanogaster strain isolated from the Seychelles archipelago. This strain has lost the ribosomal DNA (rDNA) locus on the X chromosome. Because the Y chromosome is the only other rDNA-bearing chromosome, all females carry at least one Y chromosome as the source of rDNA. Interestingly, we found that the strain also carries a truncated Y chromosome (YS) that is stably maintained in the population despite its inability to support male fertility. Our modeling and cytological analysis suggest that the Y chromosome has a larger negative impact on female fitness than the YS chromosome. Moreover, we generated an independent strain that lacks X rDNA and has a karyotype of XXY females and XY males. This strain quickly evolved multiple karyotypes: two new truncated Y chromosomes (similar to YS), as well as two independent X chromosome fusions that contain the Y-derived rDNA fragment, eliminating females' dependence on the Y chromosome. Considering that Robertsonian fusions frequently occur at rDNA loci in humans, we propose that rDNA loci instability may be one of driving forces of karyotype evolution.

NPY1R exerts inhibitory action on estradiol-stimulated growth and predicts endocrine sensitivity and better survival in ER-positive breast cancer

G Protein-Coupled Receptors (GPCRs) represent the largest superfamily of cell-surface proteins. However, the expression and function of majority of GPCRs remain unexplored in breast cancer (BC). We interrogated the expression and phosphorylation status of 398 non-sensory GPCRs using the landmark BC proteogenomics and phosphoproteomic dataset from The Cancer Genome Atlas. Neuropeptide Y Receptor Y1 (NPY1R) gene and protein expression were significantly higher in Luminal A tumors versus other BC subtypes. The trend of NPY1R gene, protein, and phosphosite (NPY1R-S368s) expression was decreasing in the order of Luminal A, Luminal B, Basal, and human epidermal growth factor receptor 2 (HER2) subtypes. NPY1R gene expression increased in response to estrogen and reduced with endocrine therapy in estrogen receptor-positive (ER+) BC cells and xenograft models. Conversely, NPY1R expression decreased in ER+ BC cells resistant to endocrine therapies (estrogen deprivation, tamoxifen, and fulvestrant) in vitro and in vivo. NPY treatment reduced estradiol-stimulated cell growth, which was reversed by NPY1R antagonist (BIBP-3226) in ER+ BC cells. Higher NPY1R gene expression predicted better relapse-free survival and overall survival in ER+ BC. Our study demonstrates that NPY1R mediates the inhibitory action of NPY on estradiol-stimulated growth of ER+ BC cells, and its expression serves as a biomarker to predict endocrine sensitivity and survival in ER+ BC patients.

Adán y Eva. Una antropología darwinista

El artículo sugiere algunas observaciones sobre una antropología darwinista planteada a partir del conocimiento científico disponible. Al efecto, señala la importancia del estudio del genoma humano como fundamento de una reflexión filosófica de segundo grado sobre la naturaleza del ser humano, subrayando las grandes similitudes entre el Homo sapiens y las especies evolutivamente más próximas. Además, a partir del estudio del ADN mitocondrial y del cromosoma Y, centra la atención en el principio de coalescencia evolutiva entre seres humanos, gracias al cual es posible afirmar que todos ellos son miembros consanguíneos de un mismo linaje. Concluye proponiendo algunas inferencias que muestran analogía entre determinados mythos y el logos científico actual

Demetylation of the sex-determining region Y gene promoter and incidence of disorder of sex development in cloned dog males.

Canine cloning is occasionally accompanied by abnormal sexual development. Some male donor cells produce cloned pups with female external genitalia and complete male gonadal dysgenesis, which is classified as an XY disorder of sex development (XY DSD). In this study, we examine the potential of 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to reduce the phenotypic abnormality XY DSD in somatic cell nuclear transfer (SCNT)- derived pups. We used a 9-year-old normal male German Shepherd dog as a cell donor. Donor cells were treated with 10 nM 5-aza-dC for 4 days before being used for SCNT. At the same stage of cell development, significantly lower levels of DNA methylation of the sex-determining region Y (SRY) promoter was observed in the treated donor cells compared to that in the untreated cells (95.2% versus 53.3% on day 4 for the control and treated groups, respectively). No significant differences were observed in the control or treatment groups concerning fusion rate, pregnancy rate (30 days or entire period), the number of pups, or the incidence of XY DSD. However, more XY DSD dogs were observed in the control group (31.25%) than in the treatment group (14.29%). Hypermethylation of the SRY promoter was observed in the XY DSD cloned pups in both the treatment (84.8%) and control groups (91.1 ± 1.4%) compared to the methylation level in the phenotypically normal male pups of the treatment (23.2 ± 20.9%) and control groups (39.1 ± 20.1%). These results suggest that 5-aza-dC treatment of donor cells can reduce the methylation level of the SRY promoter in donor cells, and thus, 5-aza-dC is advantageous for reducing the incidence of XY DSD in canine cloning.

How Neanderthals lost their Y chromosome

How Neanderthals lost their Y chromosome

Hematopoietic Stem Cells

The small population of pluripotent hematopoietic stem cells (PHSCs) in the bone marrow consists of short-term reconstituting cells (STRCs) and long-term reconstituting cells (LTRCs), based on how quickly the transplanted cells can produce progeny in an irradiated recipient. They can be “purified” using a combination of cell size; density; fluorescent dye uptake; resistance to cytotoxic chemicals; and cell-surface markers including Thy 1.1 (T), Sca-1 (S), c-kit (K), lineage (L), CD38 (38), and CD34 (34). Using five-color fluorescence-activated cell sorting the long term, very primitive mouse LTRCs are L-/lo, S+, K+, 38+, 34-, and appear to mature to L-/lo, S+, K+, 38+, 34+ cells and then to L-/lo, S+, K+, 38-, 34+; thus, STRCs acquire CD34 and lose CD38 on maturation from CD34- LTRCs. CD34 has been used to isolate PHSCs for human transplantation studies; therefore, the LTRC may be lost during this procedure. Experimental transplantation studies indicate that the best reconstitution occurs when both cell populations are present, the more mature cells activating the immature cells after myeloablation, whereas the mature cells provide negative control in normal animals. Functionally the type of assay that has been most widely used for the quantitation of mouse stem cells is the in vivo repopulating assay. Different numbers of donor cells are combined with a standard number of normal bone marrow cells. The normal cells protect against the immediate effects of myeloablation and compete with the donor stem cells. The proportions of mature cells derived from the donor stem cells are determined by the detection of a donor-specific marker, such as an isoenzyme, Y-chromosome, or congenic antigen. Similarly, using limiting dilution transplant of a donor test population of cells and a standard number of stem cell—compromised serially transplanted cells, the relative contribution of the donor cells is measured as a competitive repopulating unit. Finally, the repopulating stem cell unit assay using complete myeloablation and busulfan-treated bone marrow radioprotective support cells provides comparatively rapid and sensitive detection of the very small numbers of LTRCs present in limiting dilution transplants. This procedure utilizes busulfan because it appears preferentially stem cell toxic, and it provides radioprotective support cells that are unable to compete effectively with normal donor stem cells in the population under investigation. Stem cells are selected based on their ability to produce both lymphoid and myeloid repopulation in severely ablated mice, rather than competitive ability.

Selecting for Coupling Phase Recombination between Potyvirus Resitance and White Endosperm Colour in Maize Preferred by Farmers in Sub-Saharan Africa (SSA)


 
 
 Maize lethal necrosis (MLN) disease caused by a combined infection of Maize chlorotic mottle virus (MCMV) and any cereal infecting potyvirus is a threat to food security in Sub-Saharan Africa (SSA). Resistance to potyvirus has been extensively studied and Mdm1 gene for potyvirus resistance on chromosome 6 of maize is linked to Y1 gene for maize endosperm colour. This study is aimed at se- lecting for coupling-phase recombination of potyvirus resistance and white endosperm colour. White susceptible maize lines CML333 and CML277 were crossed with a yellow resistant line, Pa405, to produce F1 and F2 progenies. Progenies were screened using molecular markers to recover 22 white endosperm recombinants. 22 selections were advanced to F3 recombinant families, and 10 were as- sayed for their responses to Maize dwarf mosaic virus (MDMV) and Sugarcane mosaic virus (SCMV). Four families segregated for SCMV resistance, selection of homozygous recombinants within these families will provide lines appropriate for improving lines with resistance to SCMV and MLN resistance in SSA.
 KEY WORDS: MAIZE LETHAL NECROSIS (MLN), WHITE MAIZE, POTYVIRUS RESISTANCE, GENETIC RECOMBINATION, SUB-SAHARAN AFRICA.
 
 

Dos tumbas individuales calcolíticas en las inmediaciones de los dólmenes de Osorno y Simancas: estudio bioantropológico, ofrenda de perros y ‘postvida’ megalítica en el valle medio del Duero

Con motivo de presentar dos tumbas individuales en fosa inéditas, se aborda un estudio de conjunto sobre las prácticas funerarias del Calcolítico Precampaniforme en la submeseta norte española. Pese a su carácter mayoritario en el registro arqueológico, se discute la representatividad como norma de este tipo de sepulturas; se rastrean comportamientos propios de rituales de enterramiento en dos tiempos, preludio de los documentados en este mismo espacio en la Edad del Bronce; se aporta información sobre el ADN mitocondrial y sexo molecular de uno de los difuntos, y se pone el énfasis, por vez primera en el Calcolítico de la cuenca del Duero, en el protagonismo de los perros en el mundo funerario. Por último, la proximidad de las dos nuevas sepulturas a sendos dólmenes –Los Zumacales (Valladolid) y La Velilla (Palencia)? da pie a debatir sobre el inicio de la ‘postvida’ megalítica en el valle medio del Duero.

Оценка разнообразия Y-ДНК среди азербайджанцев

Оценка разнообразия Y-ДНК среди азербайджанцев

Selecting for Coupling-Phase Recombination Between Potyvirus Resistance and White Endosperm Colour in Maize Preferred by Farmers in Sub-Saharan Africa (SSA)

Maize lethal necrosis (MLN) disease caused by a combined infection of Maize chlorotic mottle virus (MCMV) and any cereal infecting potyvirus is a threat to food security in Sub-Saharan Africa (SSA). Resistance to potyvirus has been extensively studied and Mdm1 gene for potyvirus resistance on chromosome 6 of maize is linked to Y1 gene for maize endosperm colour. This study is aimed at selecting for coupling-phase recombination of potyvirus resistance and white endosperm colour. White susceptible maize lines CML333 and CML277 were crossed with a yellow resistant line, Pa405, to produce F1 and F2 progenies. Progenies were screened using molecular markers to recover 22 white endosperm recombinants. 22 selections were advanced to F3 recombinant families, and 10 were assayed for their responses to Maize dwarf mosaic virus (MDMV) and Sugarcane mosaic virus (SCMV). Four families segregated for SCMV resistance, selection of homozygous recombinants within these families will provide lines appropriate for improving lines with resistance to SCMV and MLN resistance in SSA.

Iran's Contribution to Human Proteomic Research.

Proteomics is a powerful approach to study the whole set of proteins expressed in an organism, organ, tissue or cell resulting in valuable information on physiological or pathological state of a biological system. High throughput proteomic data facilitated the understanding of various biological systems with respect to normal and pathological conditions particularly in the instances of human clinical manifestations. The important role of proteins as the functional gene products encouraged scientists to apply this technology to gain a better understanding of extremely complex biological systems. In last two decades, several proteomics teams have been gradually formed in Iran. In this review, we highlight the most important findings of proteomic research groups in Iran at various areas of stem cells, Y chromosome, infertility, infectious disease and biomarker discovery.

Identification of sorghum grain mold resistance loci through genome wide association mapping

Grain mold, caused by a consortium of pathogenic fungal species, is the most important disease of sorghum [Sorghum bicolor (L.) Moench]. Genome wide association study on 1425 diverse Ethiopian sorghum landraces identified a major grain mold resistance locus containing tightly linked and sequence related MYB transcription factor genes. The locus contains YELLOW SEED1 (Y1), a likely non-functional pseudo gene (Y2), and YELLOW SEED3 (Y3). SNPs and other sequence polymorphisms that alter the Y1 and Y3 genes correlated with susceptibility to grain mold and provided a strong genetic evidence. Accordingly, the expression of both Y1 and Y3 genes in the developing grain and glumes of a widely known susceptible sorghum line, RTx430, were severely reduced but significantly increased in the resistant line, RTx2911. In addition, the expression of flavonoid biosynthesis genes such as DIHYDROFLAVONOL 4-REDUCTASE 3 (DFR3) was significantly induced in the resistant line in response to inoculation by a mixture of spores from different molding fungi while the susceptible line displayed reduced expression. The data suggest that the MYB genes and their grain and glume specific expressions may determine the differential regulation of the flavonoid biosynthesis pathway genes, the synthesis of 3-Deoxyanthocynidins and ultimately responses to molding fungi. The study also suggested that resistance to grain mold may be negatively associated with grain functionality traits such as ‘injera’ making quality of sorghum.

The gender-specific expression of neuropeptide Y and neuropeptide Y receptors in human atrial tissue during cardiopulmonary bypass surgery.

Cardiac sympathetic nervous system is usually activated in cardiopulmonary bypass (CPB) surgery, accompanied by excessive release of norepinephrine (NE). Neuropeptide Y (NPY) has been shown to regulate NE release in the terminal of sympathetic fiber, which is a target for regulating heart function. The expression of NPY and NPY receptor (NPYR) genes in the human atrial tissues during CPB in cardiac surgery was investigated in the present study. A few discarded atrial tissues before and after CPB were collected in 22 patients with rheumatic cardiac valve diseases. The transcriptional levels of NPY and NPYRs were monitored by real-time quantitative polymerase chain reaction (RT-qPCR) method. Moreover, the correlation between the mRNA levels of NPY/NPYRs and the clinical data were investigated in detail. The mRNA levels of NPY Y1 and NPY Y5 genes were statistically attenuated in male patients after CPB. Conversely, the expression of NPY, NPY Y1 and NPY Y5 genes were enhanced in female patients. Correlation analysis suggested that there was a significant negative correlation between cardiac ejection fraction (EF) after CPB with the atrial transcriptional level of NPY in male patients. These results suggested that the expression of NPY/NPYRs in human atrial tissue during CPB was gender specific and activated NPY signaling was only identified in female patients. The elevated expression level of NPY in male patients was correlated with lower cardiac EF after CPB.

Genetic analysis for a haemophilia B family with multi nucleotides deletion mutation of F9 gene

Objective To conduct genetic diagnosis and prenatal diagnosis for a haemophilia B family with multi-nucleotides deletion mutation of F9 gene. Methods This is a genetic analysis. Whole exon mutation of the F9 gene was analyzed by PCR and Sanger sequencing for seven patients with the family of hemophilia B who consulted doctors in Henan Province People′s Hospital in April 2013. Suspected mutation was verified among non-hemophilia B members of the family and 100 healthy controls to rule out genetic polymorphism of the F9 gene. The above-mentioned detection results of hemophilia B gene, the pathogenic mutation of F9 gene in the family was clarified, and prenatal diagnosis was conducted for the female carriers in the family.It is recommended that the fetal gene detection should be conducted in amniotic fluid in the mid-term pregnancy of the female carriers of hemophilia, and then they can be informed of the non-hemophilia B fetus by the results of the gene detection. Results PCR and sequencing analysis has identified a deletion mutation of F9 gene c. 185_188delGAGA[p.Glu62Asnfs*41]in seven hemophilia B patients. This mutation induced F9 gene frame shift mutation which led to early termination of F9 gene translation because there was a termination codon TAA at the 41th codon after the mutation site. The same mutation was not found among the non-hemophilia B members of the family and the 100 healthy controls. There were eight female carriers and nine female non-carriers in the family. Upon prenatal diagnosis, the Y chromosome sex-determining gene (SRY) in amniotic fluid was positive and no deletion mutation was observed in the F9 gene c. 185_188. Conclusion The pathogenic mutation of F9 gene in the family was identified, which was helpful for prenatal diagnosis in female carriers.(Chin J Lab Med, 2018, 41: 675-679) Key words: Hemophilia B; Gene deletion; Prenatal diagnosis; Genetic testing

Perinatal Malnutrition Leads to Sexually Dimorphic Behavioral Responses with Associated Epigenetic Changes in the Mouse Brain

Childhood malnutrition is a risk factor for mental disorders, such as major depression and anxiety. Evidence shows that similar early life adversities induce sex-dependent epigenetic reprogramming. However, little is known about how genes are specifically affected by early malnutrition and the implications for males and females respectively. One relevant target is neuropeptide Y (NPY), which regulates both stress and food-intake. We studied maternal low protein diet (LPD) during pregnancy/lactation in mice. Male, but not female, offspring of LPD mothers consistently displayed anxiety- and depression-like behaviors under acute stress. Transcriptome-wide analysis of the effects of acute stress in the amygdala, revealed a list of transcription factors affected by either sex or perinatal LPD. Among these immediate early genes (IEG), members of the Early growth response family (Egr1/2/4) were consistently upregulated by perinatal LPD in both sexes. EGR1 also bound the NPY receptor Y1 gene (Npy1r), which co-occurred with sex-specific effects of perinatal LPD on both Npy1r DNA-methylation and gene transcription. Our proposed pathway connecting early malnutrition, sex-independent regulatory changes in Egr1, and sex-specific epigenetic reprogramming of its effector gene, Npy1r, represents the first molecular evidence of how early life risk factors may generate sex-specific epigenetic effects relevant for mental disorders.

Validation and application of a novel integrated genetic screening method to a cohort of 1,112 men with idiopathic azoospermia or severe oligozoospermia.

Microdeletions of the Y chromosome (YCMs), Klinefelter syndrome (47,XXY), and CFTR mutations are known genetic causes of severe male infertility, but the majority of cases remain idiopathic. Here, we describe a novel method using single molecule Molecular Inversion Probes (smMIPs), to screen infertile men for mutations and copy number variations affecting known disease genes. We designed a set of 4,525 smMIPs targeting the coding regions of causal (n=6) and candidate (n=101) male infertility genes. After extensive validation, we screened 1,112 idiopathic infertile men with non-obstructive azoospermia or severe oligozoospermia. In addition to five chromosome YCMs and six other sex chromosomal anomalies, we identified five patients with rare recessive mutations in CFTR as well as a patient with a rare heterozygous frameshift mutation in SYCP3 that may be of clinical relevance. This results in a genetic diagnosis in 11-17 patients (1%-1.5%), a yield that may increase significantly when more genes are confidently linked to male infertility. In conclusion, we developed a flexible and scalable method to reliably detect genetic causes of male infertility. The assay consolidates the detection of different types of genetic variation while increasing the diagnostic yield and detection precision at the same or lower price compared with currently used methods.

From surnames to linguistic and genetic diversity: five centuries of internal migrations in Spain.

In a previous study concerning 33,753 single Spanish surnames (considered as tokens) occurring 51,419,788 times we have shown that the present-day geography of contemporary surname variability in Spain still corresponds to the political geography of the country at the end of the Middle Ages. Here we reprocess the same database, by clustering surnames with Self-Organizing Maps (SOMs) according to their geographic distribution, to identify the monophyletic surnames showing a geo-historical origin in one of the 47 provinces of continental Spain. They are 25,714, and they occur 12,348,109 times, meaning that about 75% of the Spanish population bears a surname that had a polyphyletic origin. From monophyletic surnames we compute migration matrices accounting for the internal migrations that took place since five centuries ago, when Spanish surnames started to be patrilineally inherited. The mono/ polyphyletic classification we obtain fits ancient census data and is compatible with published molecular diversity of the Y-chromosomes associated to selected Spanish surnames. Monophyletic surnames indicate that i) the provinces exhibiting a higher percentage of autochthonous surnames are also ii) those from which emigration corresponds to a local isolation-by-distance model of diffusion and iii) those that attracted a lower number of immigrants. These are also the provinces where languages other than Castilian are spoken. We suggest that demographic stability explains linguistic resilience, as people prefer to move to areas in which the linguistic variety is more similar to their own. So far the reciprocal influence of migration and language has been investigated at local scales, here we outline how to investigate it at national scales and for time-depths of centuries.

Comparison of gene frequencies of short tandem repeats loci on Y Chromosome between offenders with initiative-aggressive behavior and impulsive-aggressive behavior

Objective To explore the distributional differences of the gene frequencies of 22 short tandem repeats loci on Y Chromosome(Y-STRs) between offenders with Initiative-aggressive behavior and impulsive-aggressive behavior, and to probe into the genetic factors of initiative-aggressive behavior and impulsive-aggressive behavior. Methods Biological samples of 271 offenders with initiative-aggressive behavior and 271 offenders with impulsive-aggressive behavior were collected and PCR compound amplification was carried out with the aid of PowerPlex Y23 System. Then the PCR products were subjected to electrophoresis and gene detection with AB3500xL gene analysis system so as to calculate and compare the alleles and haplotypes of 22 Y-STRs gene frequency in the two groups. Results The distribution of allele frequency were significantly difference in locus DYS437(P=0.022)between two groups, not in the other 21 Y-STRs loci(all P>0.05). Univarite analysis showed significant differences at allelle 14 in locus DYS437 between both groups(initiative-aggressive behavior group: 69.37%; impulsive-aggressive behavior group: 58.67%; P=0.009). Conclusion Loci DYS437 may be associated with aggressive behavior. In the group of aggressive behavior, allelle 14 on locus DYS437 may be the susceptible factor of initiative-aggressive behavior and the resistant factor of impulsive-aggressive. Key words: Initiative-aggressive behavior; Impulsive-aggressive; Human Y chromosome; Short tandem repeats(STRs); Genetic polymorphism

Prenatal diagnosis of two families with megalencephalic leukoencephalopathy with subcortical cysts

Objectives To provide genetic counseling and prenatal molecular diagnosis for two families with megalencephalic leukoencephalopathy with subcortical cysts (MLC). Methods Two MLC patients (probands 1 and 2) were admitted to the Department of Pediatrics of Peking University First Hospital in June 2011 and June 2009, respectively. Peripheral blood was collected and DNA sequencing was performed for genetic analysis for the two MLC patients and their parents. Amniotic fluid and villus of two fetuses (fetus 1 and 2) were collected at 21+4 and 12+3 weeks of gestational age from their mothers when they were pregnant again. The genomic DNA of the two fetuses was extracted and corresponding sites of MLC1 gene were sequenced. Haplotype analysis using a combination of 3 microsatellite markers (AR, DXS6807 and DXS6797) on chromosome X and sex-determining region of Y chromosome was performed to detect maternal cell contamination. Verification of the prenatal molecular diagnosis and follow-up study after birth were conducted for both fetuses. Results Macrocephaly, motor development delay and typical findings on brain MRI were identified in the two probands, and were clinically diagnosed with MLC. Compound heterozygous mutations were detected in proband 1 [c.353C>T (p.T118M) and c.803C>G (p.T268R)] and proband 2 [c.353C>T (p.T118M) and c.836T>C(p.L279P)], respectively. MLC was genetically diagnosed. Heterozygous variation in c.353[c.353C>T (p.T118M)] and wild c.803C were identified in fetus 1, and both wild c.353C and c.836T were found in fetus 2. No maternal cell contamination was detected in both fetuses. Sequencing the corresponding sites after birth confirmed the prenatal diagnosis, and the head circumference and motor development were normal in fetus 1 at 5 months old. No macrocephaly was found and no DNA sequencing was done in fetus 2 at one month old. Conclusions Genetic counseling and prenatal molecular diagnosis for MLC families combined with clinical and genetic diagnosis are important in preventing MLC. Haplotype analysis with a combination of three microsatellite markers on chromosome X and sex-determining region of Y chromosome is useful in detecting maternal cell contamination and avoiding its influence on prenatal diagnosis, and confirming the reliability of prenatal diagnosis. Key words: Megalencephalic leukoencephalopathy with subcortical cysts; Genetic leukoencephalopathy; Membrane proteins; Prenatal diagnosis