Detection of mosaic 15q11.1-q11.2 deletion encompassing NBEAP1 and POTEB in a fetus with diffuse lymphangiomatosis.

OBJECTIVE: We present cytogenetic and molecular cytogenetic diagnoses of mosaic deletion of chromosome 15q11.1-q11.2 in a fetus with diffuse lymphangiomatosis. CASE REPORT: A 33-year-old woman underwent amniocentesis at 22 weeks of gestation because of fetal diffuse lymphangiomatosis involving left-side chest, abdominal cavity, thigh and vulva, and intrauterine growth restriction. Amniocentesis revealed a karyotype of 46,XX,del(15) (q11.1q11.2)[9]/46,XX[26]. The mother had a karyotype of 46,XX. The father had a karyotype of 46,XY. The parents elected to terminate the pregnancy. A 610-g female fetus was delivered at 23 weeks of gestation with large cystic lymphangioma over the left abdomen, thigh, and vulva. The umbilical cord had a karyotype of 46,XX,del(15)(q11.1q11.2)[24]/ 46,XX[16]. The placental tissue had a karyotype of 46,XX,del(15)(q11.1q11.2)[23]/ 46,XX[17]. Array comparative genomic hybridization analysis of the umbilical cord and placenta revealed a 2.42-Mb deletion of 15q11.1-q11.2 encompassing the genes of NBEAP1 and POTEB. CONCLUSION: Deletion of 15q11.1-q11.2 encompassing NBEAP1 and POTEB may be associated with diffuse lymphangiomatosis.

The reliability of transabdominal cervical length measurement in a low-risk obstetric population: Comparison with transvaginal measurement.

OBJECTIVE: To determine the correlation between transabdominal (TA) and transvaginal (TV) cervical length measurement in a low-risk obstetric population in Taiwan. MATERIALS AND METHODS: Women with a singleton pregnancy between 20 weeks and 24 weeks of gestation underwent postvoid TA and TV cervical length measurements. Differences between the measurements obtained using the two methods were evaluated. RESULTS: Two hundred and five women agreed to participate in the study. Paired TA and TV measurements were obtained in 174 women. The mean TA cervical length was 36.0 ± 4.9 mm and the mean TV cervical length was 37.6 ± 5.4 mm. The mean TA cervical length was shorter than the mean TV cervical length by 1.6 mm. The 5(th) percentile of TA and TV cervical length was 29 mm and 29.1 mm, respectively. The discrepancies between the two methods were not significantly correlated with maternal body mass index (BMI). All women with TV cervical length <25 mm had a corresponding TA cervical length <29 mm. CONCLUSION: The TA cervical length could be obtained in the majority of the low-risk pregnant women in the present study, and the TA cervical length was closely correlated with the TV cervical length. The use of TA ultrasound could be an effective initial tool for cervical length screening in low-risk pregnant women. TA cervical length <29 mm (5(th) percentile) could be used as a cut-off value for further TV ultrasound.

Prenatal diagnosis and array comparative genomic hybridization characterization of trisomy 21 in a fetus associated with right congenital diaphragmatic hernia and a review of the literature of chromosomal abnormalities associated with congenital diaphragmatic hernia.

OBJECTIVE: Rapid genome-wide aneuploidy diagnosis using uncultured amniocytes and array comparative genomic hybridization (aCGH) is useful in pregnancy with abnormal ultrasound findings. The purpose of this report is to report a case of right congenital diaphragmatic hernia (CDH) associated with trisomy 21 diagnosed prenatally by aCGH and to review the literature of chromosomal abnormalities associated with CDH. CASE REPORT: A 29-year-old woman was referred for genetic counseling at 25 weeks of gestation because of fetal CDH. The pregnancy was uneventful until 25 weeks of gestation when level II ultrasound detected isolated right CDH. Ultrasound showed that the liver and gallbladder were located in the right hemithorax, and there was levocardia. Fetal magnetic resonance imaging confirmed the diagnosis of right CDH with the gallbladder and part of the liver appearing in the right hemithorax and the heart shifting to the left hemithorax. Amniocentesis was immediately performed. About 10 mL of amniotic fluid was sent for aCGH analysis by use of the DNA extracted from uncultured amniocytes, and 20 mL of amniotic fluid was sent for conventional cytogenetic analysis. aCGH analysis revealed the result of arr 21p11.2q22.3 (9,962,872-48,129,895) × 3, consistent with the diagnosis of trisomy 21. Conventional cytogenetics revealed a karyotype of 47,XY,+21. Postnatally, polymorphic DNA marker analysis using DNAs extracted from the placenta and parental bloods showed a heterozygous extra chromosome 21 of maternal origin consistent with the result of maternal meiosis I nondisjunction. CONCLUSION: Prenatal diagnosis of right CDH should raise a suspicion of chromosomal abnormalities especially trisomy 21 and the association of Morgagni hernia.

Interphase fluorescence in situ hybridization characterization of mosaicism using uncultured amniocytes and cultured stimulated cord blood lymphocytes in prenatally detected Pallister-Killian syndrome.

OBJECTIVE: This study aims to present molecular cytogenetic characterization of Pallister-Killian syndrome (PKS). MATERIALS AND METHODS: A 37-year-old woman underwent amniocentesis at 18 weeks of gestation. Amniocentesis revealed a karyotype of 47,XY,+i(12)(p10)[6]/48,XY,+i(12)(p10)×2[1]/46,XY[6]. Repeated amniocentesis was performed at 20 weeks of gestation. Array comparative genomic hybridization (aCGH) was performed using uncultured amniocytes, cord blood, and skin. Quantitative fluorescent polymerase chain reaction (QF-PCR) was performed using uncultured amniocytes and parental bloods. Interphase fluorescence in situ hybridization (FISH) analysis was performed using uncultured amniocytes and cultured stimulated cord blood lymphocytes. Conventional cytogenetic analysis was performed using cultured cells from amniotic fluid, skin, placenta, umbilical cord, and cord blood. RESULTS: Repeated amniocentesis revealed a mosaic tetrasomy 12p level of 25% (10/40), cultured cord blood lymphocytes had no mosaicism, cultured skin fibroblasts had a mosaic tetrasomy 12p level of 52.5% (21/40), umbilical cord fibroblasts had a mosaic tetrasomy 12p level of 72.5% (29/40), and the placental cells had a mosaic tetrasomy 12p level of 2.5% (1/40) on conventional cytogenetics. An aCGH analysis revealed that the increases in gene dosage in 12p for uncultured amniocytes, skin, and cord blood were the log2 ratios of 0.9, 0.7, and 0.7, respectively. Interphase FISH on uncultured amniocytes revealed a mosaic level of 73.1% (49/67) (tetrasomy 12p: 33; hexasomy 12p: 16). Interphase FISH analysis of stimulated cultured cord blood lymphocytes revealed a mosaic level of 58.3% (60/103) (tetrasomy 12p: 51; hexasomy 12p: 9). CONCLUSION: In the diagnosis of PKS by conventional culture cytogenetics, cord blood samplings and placental samplings are prone to a negative result when compared with amniocentesis. Whenever cord blood sampling is applied for prenatal diagnosis of PKS, aCGH on uncultured cord blood or interphase FISH on cultured cord blood can be used for the diagnosis, in addition to conventional cytogenetics.