Trisomy 18 mosaicism in an adult with normal intelligence

Abstract

A healthy 30-year-old woman was discovered unexpectedly to have trisomy 18/normal chromosome mosaicism. She was ascertained because of a history of three spontaneous abortions following the birth of a healthy son. Trisomy 18 was present in 18% of her lymphocytes and 2% of her cultured skin fibroblasts. She had several minor malformations associated with trisomy 18 syndrome. She is, to our knowledge, the first person who has clinical stigmata of trisomy 18 but has normal intelligence and leads a normal family life.

Trisomy 18 mosaicism in an adult woman with normal intelligence and history of miscarriage

“…We report a case of trisomy 18 mosaicism with normal intelligence and mild unspecific dysmorphic features. To our knowledge, only two similar cases have b e e n reported to date (Kohn and Shoat 1987;Beratis et al 1972) (Table 1). …”

Transcriptomic analysis of cell-free fetal RNA suggests a specific molecular phenotype in trisomy 18

“…The high mortality rate is typically due to the presence of cardiac and renal malformations, feeding difficulties that result in aspiration pneumonia, sepsis, and apnea caused by central nervous system abnormalities. Long-term survival in trisomy 18 has been reported, but this occurs primarily in the context of mosaicism (Kohn et al 1987; Bettio et al 2003). Interestingly, in mosaic individuals there is no correlation between the physical and intellectual findings and the percentage of trisomic cells found in either peripheral leukocytes or skin fibroblasts (Mewar et al 1993).…”

Trisomy 18 mosaicism in a woman with normal intelligence, pigmentary dysplasia, and an 18 trisomic daughter

“…They are usually mentally severely retarded with a variety of anomalies [Murano et al, 1991]. There is another group of mosaic individuals: 7 women and a 13-year-old girl, with a low frequency of 18-trisomic cells, normal or mildly retarded intelligence, and minor anomalies [Beratis et al, 1972;Bensen and Steele, 1985;Kohn and Shohat, 1987;Gersdorf et al, 1990;Graham et al, 1992;Sarigol and Rogers, 1994;Butler, 1994;Collins et al, 1995]. Two of them were diagnosed after delivering malformed stillborn infants [Kohn and Shohat, 1987;Gersdorf et al, 1990].…”