Mosaic trisomy 4: Long-term outcome on the first reported liveborn.

In a previous report, we described the first liveborn with trisomy 4 mosaicism [Marion et al. (1990) Am J Med Genet 37:362-365]. To our knowledge, since our original report, there have been only four additional reports of a prenatal diagnosis of mosaic trisomy 4 resulting in a liveborn child [Hsu et al. (1997) Prenat Diag 17:201-242; Kuchinka et al. (2001) Prenat Diag 21:36-39; Wieczorek et al. (2003) Prenat Diag 23:128-133; Zaslav et al. (2000) Am J Med Genet 95:381-384]. Three of the more recent reports lacked confirmation of the mosaicism in tissue samples collected from the child after delivery, and likely represent cases of confined placental mosaicism. We recently examined our original patient, N.J., in an effort to provide long-term follow-up. N.J. is currently 14-years-old, and is enrolled in both special education and mainstream eighth grade classes at a local public middle school. Although she generally scores below average on standardized intellectual tests, her verbal skills and social interactions are more age appropriate. Our initial report described abnormalities of N.J.'s right hand and right ear, for which several reconstructive surgeries have been performed. A current medical concern is her entrance into puberty, as menarche has not yet occurred, and asymmetrical breast development is present. Overall, N.J. has developed into a generally healthy adolescent with low-normal intellect. This report demonstrates the importance of long-term follow-up in providing accurate counseling for rare chromosomal disorders.