Wiedemann-Beckwith syndrome in one of monozygotic twins.

Abstract

The proband, first of the twins, weighed 2430 g (> 10th centile), the co-twin weighing 2130 g (<10th centile). The most striking features on examination of the proband were macroglossia, moderate sized exomphalos, and widely spaced nipples. No indentation of the ear lobules was noted. Early hypoglycaemia was managed with dextrose infusion, and the exomphalos was corrected within the first 24 hours of life. The second twin was of normal appearance but was small for gestational age. There were no neonatal problems. Examination of the parents did not reveal any ear creases, posterior pits, or divarication of rectus muscles, and they were not of large birthweight.After initial catch up growth the second twin's growth variables at the age of 18 months continued along the 10th centile, and developmental assessment at that age was within normal limits. The proband had feeding difficulties related to her macroglossia, and partial glossectomy was eventually performed at the age of 17 months. Despite these problems her growth has continued along the 50th centile for height, weight, and occipitofrontal head circumference. At the age of 18 months her development was delayed by six months. No abdominal mass was detected at any time.Investigations to determine zygosity showed both twins to be of blood groups A, rr. They were identical when typed for Kell, Fya, Jka, P1, and MNS. In the HLA system both were A 3, 30, B7, 13, and CW 7. The parents were also typed and the final probability of monozygosity was 0 995. Chromosomal preparations were made from cells cultured from peripheral blood of both twins and stained to reveal both C and G bands. No differences were observed in C band polymorphisms, thus supporting monozygosity, and no abnormality was detectable on any chromosome of either child. Chromosome 11 was particularly closely examined on prometaphase cells. Discussion

Monozygotic twinning and Wiedemann‐Beckwith syndrome

“…These two sets of twins bring the total number of WBS MZ twins reported in the literature to 11 sets [Berry et al, 1980;Bose et al, 1985;Litz et al, 1988;Olney et al, 1988;Estabrooks et al, 1989: Lubinsky days gestation [James, 19881. This coincides with the period when MZ twinning could be occurring [Boklage, 19811 and it i s possible that X-inactivation may itself promote MZ twinning.…”

“…Monozygotic (MZ) twinning is a frequent observation in WBS [Berry et al, 1980;Bose et al, 1985;Litz et al, 1988;Olney et al, 1988;Estabrooks et al, 19893. Frequent MZ twinning has not been reported in other disorders associated with genomic imprinting such as the Prader-Willi syndrome and Angleman syndrome [Knoll et al, 19893.…”

Beckwith–Wiedemann syndrome

“…There have been multiple reports of monozygotic twins with BWS [Berry et al, 1980;Bose et al, 1985;Litz et al, 1988;Olney et al, 1988;Chien et al, 1990;Clayton-Smith et al, 1992;Franceschini et al, 1993;Orstavik et al, 1995;Leonard et al, 1996]. We had the opportunity to investigate a cohort of monozygotic twins discordant for BWS.…”

New chromosome 11p15 epigenotypes identified in male monozygotic twins with Beckwith-Wiedemann syndrome

“…Many monozygotic twin pairs with BWS have been reported in the literature (Bose et al, 1985;Brown, 1986;Litz et al, 1988;Chien et al, 1990;Clayton-Smith et al, 1992;Franceschini et al, 1993;Leonard et al, 1996;Schier et al, 2000;Weksberg et al, 2002). Monozygotic twins result from a single fertilization and are often said to be genetically identical, although it has been repeatedly reported that there are differences between monozygotic twins in terms of discordance for disease or chromosomal abnormalities (Machin, 1996).…”