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Megacystis-microcolon-intestinal-hypoperistalsis syndrome (MMIHS) is a rare and severe disorder characterized by functional obstruction in the urinary and gastrointestinal tract. The molecular basis of this condition has been defined recently. Heterozygous variants in ACTG2, homozygous mutations in LMOD1, MYLK, and MYH9 were related to the pathogenesis of the syndrome, which encodes proteins involved in the process of smooth muscle contraction, supporting a myopathic basis for the disease. Recent studies have identified homozygous or compound heterozygous variants in MYH11 as a candidate gene of MMIHS. In this report, we described a nonconsanguineous Chinese family with three male fetuses affected with megacystis. Trio-targeted exome sequencing identified compound heterozygous variants, c.2051 G > A (p.R684H) and c.3540_3541delinsTT (p.(E1180D, Q1181Ter)), in MYH11 (NM_001040114). The variants were inherited from the parents, respectively. Western blotting showed a marked decrease in MYH11 protein in the proband’s umbilical cord tissue compared with the control sample. The study’s results confirmed that MYH11 is a candidate gene for MMIHS with autosomal recessive (AR) inheritance and expanded the mutation spectrum for this clinical condition. Combining clinical phenotype with molecular diagnosis may enable the identification of candidate genes for potential monogenic diseases and facilitate accurate genetic counseling, informed decision-making, and prenatal diagnosis.

Background Balanced complex chromosome rearrangement (CCR) carriers are phenotypically normal but at high risk of reproductive failure, recurrent miscarriages, and affected offspring, so that cytogenetic characterizations of CCR carriers are crucial. Methods We report a case of CCR: 46,XX, t(6;15;10;9)(q13;q15;p11.2;q34.3) ins(9;8)(q22.33;q21.1q21.3). The peripheral blood was collected for karyotyping, single nucleotide polymorphism array (SNP-array) analysis, and whole genome mate-pair sequencing. Results The patient's karyotype is detected and identified as 46,XX, t(6;15;10;9)(q13;q15;p11.2;q34.3) ins(9;8) (q22.33;q21.1q21.3), with no significant duplication and deletion found by SNP-array analysis. There are 16 break-points among chromosomes 6, 8, 9, 10, and 15 identified by whole genome sequencing. Conclusions With a variety of detection techniques, we can deeply study the genetic characteristics of CCRs, thus providing a basis for genetic counseling and choice of fertility.

Background X-linked creatine transporter deficiency (OMIM#300036,CRTR-D) is characterized by cerebral creatine deficiency, intellectual disabilities, severe speech impairment, seizures and behavioral problems. Mutations in the creatine transporter gene SLC6A8, a member of the solute-carrier family 6 mapped to Xq28, have been reported to cause the creatine transporter deficiency. Case presentation The proband presented at 5 yrs. 1 month of age with delays in intellectual and development, seizures and behavioral problems. A novel missense mutation, c.1181C > A (p.Thr394Lys), in the SLC6A8 gene (NM_005629.3) was detected via targeted exome sequencing, and then validated by Sanger sequencing. Multiple in silico variant effect analysis methods, including SIFT, PolyPhen2, PROVEAN, and Mutation Taster predicted that this variant was likely damaging or diseasing-causing. This hemizygous variation was also identified in the affected brother with the same clinical condition and inherited from the heterozygous carrier mother. The diagnosis was suggested by increased urinary creatine/creatinine (Cr:Crn) ratio and markedly reduced creatine content peak by brain proton magnetic resonance spectroscopy (MRS). The proband’s mother became pregnant with a 3rd sibling, in whom the Sanger sequencing result of c.1181C > A was negative. Conclusion The novel mutation c.1181C > A in the SLC6A8 gene reported in a Chinese family has expanded the mutation spectrum of CRTR-D. The combination of powerful new technologies such as targeted exome sequencing with thorough systematic clinical evaluation of patients will improve the diagnostic yield, and assist in genetic counselling and prenatal diagnosis for suspected genetic disorders. Electronic supplementary material The online version of this article (10.1186/s12881-018-0707-5) contains supplementary material, which is available to authorized users.

To assess the value of G-banded karyotyping in combination with multiplex ligation-dependent probe amplification (MLPA) as a tool for the detection of chromosomal abnormalities in fetuses with congenital heart defects.The combined method was used to analyze 104 fetuses with heart malformations identified by ultrasonography. Abnormal findings were confirmed with chromosomal microarray analysis (CMA).Nineteen (18%) fetuses were found to harbor chromosomal aberrations by G-banded karyotyping and MLPA. For 93 cases, CMA has detected abnormalities in 14 cases including 10 pathogenic copy number variations (CNVs) and 4 CNVs of uncertain significance (VOUS). MLPA was able to detect all of the pathogenic CNVs and 1 VOUS CNV.Combined use of G-banded karyotyping and MLPA is a rapid, low-cost and effective method to detect chromosomal abnormalities in fetuses with various heart malformations.

To identify potential mutation of SLC22A5 gene in a 5-month-old boy affected with primary carnitine deficiency and provide genetic counseling and prenatal diagnosis for the members of his family.DNA was extracted from peripheral blood samples derived from the proband, his parents and elder sister, as well as amniotic fluid from his pregnant mother. All of the 10 exons of the SLC22A5 gene were amplified by PCR and subjected to Sanger sequencing. The amniotic fluid sample was also subjected to G-banded karyotyping and multiplex ligation-dependent probe amplification (MLPA).A homozygous mutation c.760CT (p.R254X) of the SLC22A5 gene was detected in the proband. Heterozygous mutation c.760CT (p.R254X) was also found in other family members including the fetus. The karyotyping and chromosomal microdeletion testing for the amniotic fluid sample were both normal.The newly identified homozygous nonsense c.760CT (p.R254X) mutation of the SLC22A5 gene probably underlies the primary carnitine deficiency of the proband. Genetic counseling and prenatal diagnosis have been provided for this family.

Background The aims of this study were to evaluate the clinical utility of multiplex ligation-dependent probe amplification (MLPA) and array comparative genomic hybridization (aCGH) analyses on prenatal cases and to review prenatal ultrasound findings of cytogenomic syndromes. Results Of the 54 prenatal cases analyzed, cytogenomic abnormalities were characterized in 14 cases. In four fetuses with abnormal ultrasound findings, a 40.701 Mb duplication of 8q22.3-q24.3 and a 23.839 Mb deletion of 7q33-q36.3 derived from a paternal balanced translocation, a de novo 13.062 Mb deletion of 11q24.1-q25 for Jacobsen syndrome, a de novo 19.971 Mb deletion of 7q11.23-q21.3 for type 1 split-hand/foot malformation (SHFM1), and a de novo 28.909 Mb duplication of 3q21.1-q25.1 were detected. A 699.8 Kb deletion at 5p15.33 for Cri du Chat syndrome was confirmed in a fetus with abnormal MLPA result. A fetus with abnormal maternal screening was detected with a de novo distal 1.747 Mb duplication at 2q37.1-q37.2 and a 6.664 Mb deletion at 2q37.2-q37.3. Of the eight cases referred by history of spontaneous abortions, derivative chromosomes 11 from paternal carriers of a balanced 8q/11q and a 10q/11q translocation were noted in two cases, simple aneuploids of trisomy 2 and trisomy 21 were seen in three cases, and compound aneuploids of two or three chromosomes were found in three cases. Post-test genetic counseling was performed with detailed genomic information and well characterized postnatal syndromic features. Conclusions These results demonstrated that coupling MLPA screening and aCGH analysis are a cost-effective approach to detect cytogenomic abnormalities in a prenatal setting. The aCGH analysis provided not only genomic maps of breakpoints and gene content of imbalanced regions but also better inference of related phenotypes for genetic counseling. Prenatal ultrasound findings reported in the literature for Jacobsen syndrome, SHFM and Cri du Chat syndrome were summarized for use as diagnostic references.

To identify potential mutations among three sisters from a Chinese family suspected with Cockayne syndrome for growth and psychomotor retardation, and to offer genetic counseling and prenatal diagnosis for the family.G-banded karyotyping, microarray comparative genomic hybridization (CM-CGH), whole genome exon high-throughput sequencing and Sanger sequencing were employed to identify potential genetic variations for the three patients and their parents.Whole exome sequencing has identified two novel missense mutations, i.e., c.1595AG (p.Asp532Gly) and c.1607TG (p.Leu536Trp), in exon 7 of excision repair cross-complementing rodent repair deficiency, complementation group 6 (ERCC6) gene. Sanger sequencing confirmed that all of the three sisters have inherited one of the mutations (c.1607TG) from their father and another (c.1595AG) from their mother.Three sisters have all been identified as double heterozygote for mutations c.1607TG and c.1595AG and were diagnosed with Cockayne syndrome.

To use array comparative genomic hybridization (array-CGH) and multiplex ligation-dependent probe amplification (MLPA) to detect unbalanced rearrangements in 4 cases suspected to have chromosome disease but were undetected with conventional karyotype analysis, and to assess the applicability of array-CGH and MLPA for detection of unbalanced translocation.Genomic DNA was extracted with standard procedures. All cases were analyzed by array-CGH and subtelomeric MLPA.All of the cases were identified to have unbalanced translocations by array-CGH analysis, among which 3 were consistent with subtelomeric MLPA analysis. For the remaining one, its chromosomal abnormality was not detected by MLPA as the imbalance has occurred outside of target regions.Both array-CGH and MLPA techniques can complement conventional karyotyping for detecting unbalanced translocations. The combination features both high resolution and efficiency for clinical use.

To perform mutation analysis for a female with multiple epiphyseal dysplasia (MED) and provide pre-symptomatic and prenatal diagnosis.Mutation screening of cartilage oligomeric matrix protein (COMP) gene was carried out through targeted next-generation DNA sequencing and Sanger sequencing.A novel c.956 AT resulting in substitution of Aspartic acid 319 for Valine (p.Asp319Val) has been identified in exon 9 of the COMP gene in the patient. As predicted by a SIFT software, above mutation can cause damage to the structure of COMP protein.A novel c.956 AT substitution mutation has been identified in a patient featuring MED.

To analyze the chromosome aberration in a full-term male neonate with low birth weight, and to explore the possible causes for growth retardation in intrauterine development for the neonate.Genomic DNA was extracted from peripheral leukocytes of the neonate. Detection of genomic DNA copy number gain and loss was performed using microarray comparative genomic hybridization. Chromosome karyotype was obtained from cultured lymphocytes for the neonate and his parents in order to identify the origin of chromosome aberration.Gain of 10q25.2--qter (22 Mb) was observed in the full-term neonate with low birth weight. In addition, one chromosomal region, 15q26.2--qter (5 Mb) was lost. The karyotype of the neonate was 46, XY, -15, +der(15), t(10;15)(q25;q26)pat.The full-term neonate with low birth weight had a partial trisomy of 10q25.2--qter with a partial monosomy of 15q26.2--qter, both of them may contribute to the growth retardation in intrauterine development for the neonate case.

Background The low copy repeats (LCRs) in chromosome 15q11-q13 have been recognized as breakpoints (BP) for not only intrachromosomal deletions and duplications but also small supernumerary marker chromosomes 15, sSMC(15)s, in the forms of isodicentric chromosome or small ring chromosome. Further characterization of copy number changes and methylation patterns in these sSMC(15)s could lead to better understanding of their phenotypic consequences. Methods Routine G-band karyotyping, fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH) analysis and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay were performed on two Chinese patients with a sSMC(15). Results Patient 1 showed an isodicentric 15, idic(15)(q13), containing symmetrically two copies of a 7.7 Mb segment of the 15q11-q13 region by a BP3::BP3 fusion. Patient 2 showed a ring chromosome 15, r(15)(q13), with alternative one-copy and two-copy segments spanning a 12.3 Mb region. The defined methylation pattern indicated that the idic(15)(q13) and the r(15)(q13) were maternally derived. Conclusions Results from these two cases and other reported cases from literature indicated that combined karyotyping, aCGH and MS-MLPA analyses are effective to define the copy number changes and methylation patterns for sSMC(15)s in a clinical setting. The characterized genomic structure and epigenetic pattern of sSMC(15)s could lead to further gene expression profiling for better phenotype correlation.