Isochromosome 18q in a fetus with congenital megacystis, intra-uterine growth retardation and cloacal dysgenesis sequence

Abstract

We present the first report of a female fetus with concomitant isochromosome 18q [i(18q)] and cloacal dysgenesis sequence. Prenatal sonographic examination at 15 weeks' gestation showed intra‐uterine growth retardation, a normal brain, a normal spine, congenital megacystis and oligohydramnios. The pregnancy was terminated. The abortus displayed dysmorphic features of a high forehead, hypertelorism, a prominent nose with a bulbous tip, median cleft lip and palate, micrognathia, low‐set ears, a short neck, a joint contracture at the wrist, prominent heels and pseudo‐hermaphroditism. Necropsy confirmed an imperforate anus, megacystis, a phallic structure and cloacal dysgenesis sequence. Postnatal chromosomal investigation proved a pure de novo i(18q). Molecular genetic analysis by polymorphic microsatellite markers confirmed the maternal origin of the aberrant chromosome. The coexistence of cloacal dysgenesis sequence and i(18q) in this case shows a correlation between the disturbance of the caudal developmental field and the chromosomal abnormality with monosomy 18p and trisomy 18q. Our presentation also demonstrates the importance of perinatal cytogenetic analysis in malformed fetuses in order to uncover underlying genetic disorders. Copyright © 1998 John Wiley & Sons, Ltd.

Autosomal Dominant Nonsyndromic Cleft Lip and Palate: Significant Evidence of Linkage at 18q21.1

“…Schinzel et al 70 reported three subjects with the 18q syndrome associated with various developmental anomalies and cleft palate. An isochromosome 18q in a fetus with congenital megacystis, growth retardation, and cleft lip and palate was reported by Chen et al 59 Partial deletion of 18q in a patient with bilateral complete cleft lip was reported by Fujimoto et al 68 Cody et al 55 analyzed 42 individuals with deletions of 18q and observed several subjects with craniofacial abnormalities, including NSCL/ P, associated with breakpoints at 18q21.1, 18q21, and 18q21.2.…”

“…Numerous reports indicate that chromosome 18-related anomalies are associated with increased incidence of NSCL/P, including deletion of 18q [53][54][55][56][57] and full or partial trisomy 18 involving the region 18q21. 21,22, [58][59][60][61][62][63][64][65][66][67][68][69] Niedrist et al 22 analyzed 352 cases of trisomy 18 from northeastern Switzerland and found that 14% of the subjects had facial clefts. Schinzel et al 70 reported three subjects with the 18q syndrome associated with various developmental anomalies and cleft palate.…”

Prenatal diagnosis and molecular cytogenetic analysis of a de novo isodicentric chromosome 18

“…The typical phenotype of i(18q) is very comparable to complete trisomy 18 and includes severe growth retardation, occipital prominence, low set ears, downward-slanting palpebral fissures, overlapping flexed fingers, rocker-bottom feet, congenital heart defects, and skeletal abnormalities. The monosomy 18p (18p-) often results in psychomotor retardation, short webbed neck, low posterior hairline, hypospadias, male genital anomalies and holoprosencephaly 67. The present fetus who had 18p11.21→qter duplication and 18p11.21→pter deletion demonstrated typical features of trisomy 18, including ventricular septal defect, limbs malformations and skeletal abnormalities.…”

Clinical challenges in the management of a prenatally diagnosed cloacal malformation

“…However, due to the high variability of cloacal anomalies, they are frequently misdiagnosed (Peña and Levitt 2003). US characteristics may include megacystis, oligohydramnios, hydronephrosis, intra‐abdominal cysts, perineal mass, fetal ascites, calcified meconium and intrauterine growth retardation (Chen et al . 1998; Qureshi et al .…”