1/6. A trisomy 2 fetus with severe neural tube defects and other abnormalities.Examination of an abortus from a 13 week miscarriage revealed a fetus of around 9 weeks developmental age with multiple abnormalities including microcephaly, iniencephaly and encephalocele continuous with cervical and thoracic spina bifida, whose karyotype was subsequently shown to be 47,XY, 2.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
2/6. Molecular cytogenetic characterization of multiple intrachromosomal rearrangements of chromosome 2q in a patient with Waardenburg's syndrome and other congenital defects.At 6 years of age, a boy with bilateral sensorineural deafness, lateral displacement of inner canthi, a bulbous nasal tip, synophrys, and cryptorchidism was clinically diagnosed as having Waardenburg's syndrome type I (WS-1). In addition, he had a lumbar spina bifida with hydrocephalus shunted on the second day of life and severe mental retardation with a head circumference at the fifth percentile. Neither parent showed signs of WS-1, and the family history was negative. Because of the WS-1 features, attention was focused on the PAX3 location in 2q, at which time a de novo paracentric inversion of 2q23-q37.1 was noted. Subsequent high-resolution chromosome analysis 8 years later indicated a complex rearrangement involving regions 2q31-q35 and 2q13-q21. Whole chromosome painting and high-resolution comparative genomic hybridization yielded negative results for any translocation, duplication, or deletion of any chromosome segments. Sequencing of the PAX3 gene yielded no detectable mutation. Fluorescent in situ hybridization (FISH) studies with human BAC clones revealed five breakpoints in chromosome 2q resulting in two paracentric inversions and one insertion, the karyotype being interpreted as 46,XY,der(2)inv(2)(q13q21)inv(2)(q21q24.2)ins(2)(q24.2q33q35). In this extremely rare chromosomal rearrangement, the FISH result showed a breakpoint at 2q35 being proximal to and without involvement of the PAX3 gene. While further studies continue, possible interpretations include involvement of a regulatory gene(s) for PAX 3 and other genes at the other breakpoints related causally to the spina bifida and mental retardation.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
3/6. Second-trimester diagnosis of complete trisomy 9 associated with abnormal maternal serum screen results, open sacral spina bifida and congenital diaphragmatic hernia, and review of the literature.OBJECTIVES: To present the prenatal diagnosis of complete trisomy 9 and to review the literature CASE: A 25-year-old primigravida woman was referred for amniocentesis at 19 weeks' gestation because of abnormal maternal screen results showing an elevated maternal serum alpha-fetoprotein (MSAFP) level and a low maternal serum free beta-human chorionic gonadotrophin (MSfreebeta-hCG) level. RESULTS: Genetic amniocentesis revealed a karyotype of 47,XX, 9 in the amniocytes and an elevated amniotic fluid AFP level. ultrasonography demonstrated intrauterine growth restriction, left congenital diaphragmatic hernia, fetal ascites, a sacral spina bifida, a horseshoe kidney, and absence of amniotic fluid. Ultrafast magnetic resonance imaging scans further depicted detailed anatomical configurations of the major congenital malformations. The pregnancy was terminated subsequently. The proband postnatally manifested characteristic facial dysmorphism, limb deformities, and an open sacral spina bifida with myelomeningocele. cytogenetic analysis of the skin fibroblasts revealed a karyotype of 47,XX, 9. Molecular studies of various uncultured fetal tissues using microsatellite markers confirmed a diagnosis of complete trisomy 9 resulting from a meiotic I nondisjunction error of maternal origin. CONCLUSION: Complete trisomy 9 can be identified prenatally with advanced maternal age, sonographically detected fetal structural abnormalities, and abnormal maternal serum screen results. Fetuses with complete trisomy 9 may be associated with congenital diaphragmatic hernia, an open sacral spina bifida, elevated MSAFP, and low MSfreebeta-hCG. We suggest detailed prenatal imaging investigations and genetic analyses of multiple fetal tissues when a prenatal diagnosis of trisomy 9 is made.- - - - - - - - - - ranking = 2keywords = karyotype (Clic here for more details about this article) |
4/6. Triploid partial molar pregnancy detected through maternal serum alpha-fetoprotein and HCG screening.BACKGROUND: Screening for down syndrome using maternal serum alpha-fetoprotein (MSAFP) and hCG, with or without unconjugated estriol (E3), has become standard practice in much of the united states. When both MSAFP and hCG are elevated, the possibility of a partial molar pregnancy with fetal neural tube or abdominal-wall defect should be added to the differential diagnosis, as illustrated by this case. CASE: A 22-year-old woman had elevated MSAFP and hCG levels on routine screening at 16 weeks' gestation. Ultrasound examination suggested a neural tube defect and a thickened placenta. amniocentesis was performed. She very rapidly developed preeclampsia. fluorescence in situ hybridization showed three distinct spots for the three probes tested. A triploid karyotype was confirmed with standard cytogenetic analysis. The fetus had an open neural tube defect, and placental pathology was consistent with a partial hydatidiform mole. CONCLUSIONS: A possible partial molar pregnancy with abdominal-wall or open neural tube defect should be added to the differential diagnosis for interpreting down syndrome screens when both MSAFP and hCG are elevated. A presumptive diagnosis of triploidy using fluorescence in situ hybridization was important in the management of this pregnancy.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
5/6. Cebocephaly, alobar holoprosencephaly, spina bifida, and sirenomelia in a stillbirth.Cebocephaly and sirenomelia are uncommon birth defects. Their association is extremely rare; however, the presence of spina bifida with both conditions is not unexpected. We report on a female still-birth with cebocephaly, alobar holoprosencephaly, cleft palate, lumbar spina bifida, sirenomelia, a single umbilical artery, and a 46,XX karyotype, but without maternal diabetes mellitus. Our case adds to the examples of overlapping cephalic and caudal defects, possibly related to vulnerability of the midline developmental field or axial mesodermal dysplasia spectrum.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |
6/6. False-positive diagnosis of spina bifida in a fetus with triploidy.BACKGROUND: neural tube defects can be difficult to diagnose using ultrasound. Cranial markers, such as the lemon and banana signs, are useful sonographic findings that alert the ultrasonographer to examine the spine more carefully. The false-positive rate for the banana sign has been reported previously as zero. CASE: A patient with elevated maternal serum alpha-fetoprotein presented for a fetal ultrasound examination. Findings on the scan included a lemon sign, a banana sign, an effaced cisterna magna, and splayed lumbar vertebrae. After pregnancy termination, no spinal abnormality was detected on autopsy. x-rays of the fetal spine demonstrated narrowing in the thoracic spine. The karyotype of the fetus was 69,XXY. CONCLUSION: The sonographic cranial findings suggestive of a neural tube defect were misleading in this case.- - - - - - - - - - ranking = 1keywords = karyotype (Clic here for more details about this article) |