Two cases of the caudal duplication anomaly including a discordant monozygotic twin

Abstract

We present two unrelated patients with various duplications in the caudal region. One patient presented with a duplication of the distal spine from L4, left double ureter, duplication of the vagina and cervix, and duplication of the distal colon. The second patient was diagnosed with a duplication of the colon, bladder, vagina and uterus. The first patient had an unaffected monozygotic twin sister. Dominguez et al. [1993: Am J Dis Child 147:1048-1052] presented six similar cases, and introduced the name "caudal duplication syndrome." The pathogenesis of the caudal duplication anomaly is unclear. The possibility of a polytopic primary developmental field defect or a disruptive sequence are discussed. On the other hand, somatic or germline mutations in certain developmental genes could be involved, as illustrated by the mouse mutations disorganisation and fused. DNA-analysis of the AXIN1 gene, the human homologue of the gene responsible for fused, performed in our first patient, did not show any apparent pathogenic mutation.

Prenatal diagnosis of submicroscopic chromosomal aberrations in fetuses with ventricular septal defects by chromosomal microarray‐based analysis

“…Case 30 had a 273-Kb duplication in chromosome 16p13.3 that involved one OMIM gene, AXIN1, which is associated with a caudal duplication anomaly and hepatocellular carcinoma. 35,36 The parental samples were unavailable; thus, the clinical significance of this fetal CNV was uncertain. Due to the complex cardiac abnormalities, the parents opted to terminate the pregnancy, and the absence of the left ear was observed at autopsy after not being detected by prenatal ultrasound.…”

The Use of Mouse Models to Study Epigenetics

“…In one case, a twin pair was identified discordant for a caudal duplication anomaly. Given the role of Axin in axis formation , AXIN1 was sequenced but no mutation was found (Kroes et al 2002). Rather, the affected twin displayed DNA hypermethylation of the AXIN1 promoter, compared with the unaffected twin (Oates et al 2006).…”

Non‐identical monozygotic twins, intermediate twin types, zygosity testing, and the non‐random nature of monozygotic twinning: A review

“…MZ twins concordant for omphalocele, exstrophy, imperforate anus, spinal defects (OEIS) have been reported [Lee et al, 1999]. In addition, MZ twins discordant for caudal duplication have been described [Kroes et al, 2002]. MC,MA twins discordant for urorectal septum malformation have been reported [Achiron et al, 2000].…”