A case of trisomy 22 with a probable Robertsonian translocation 21/22

Abstract

A 2-year-old girl with a prabable trisomy-22 translocation is described. The principal clinical symptoms described by the authors who have reported cases with proved trisomy 22 are presented. A probable 46,XX,-21,+t(21q;22q) karyotype was established in the patient. The proband's clinical picture is compared with other trisomy 22 cases described in the literature. The incidence of this trisomy among the human population is discussed.

Possible isochromosome 22 leading to trisomy 22

“…Hirschhorn et al [1973] reported the first Gbanded proven case. All reported cases have had 47 chromosomes due to an additional chromosome 22, except for one report with a possible t(21;22) [Lalchev et al, 1978] and one with a 46,XX,+idic(22)(qter→p1125:: p1125→qter) karyotype [Voiculescu et al, 1987]. We describe a further case of trisomy 22 with a modal chromosome number of 46 but with a monocentric, possible isochromosome.…”

Non‐mosaic trisomy 22: a report of 2 cases

“…The outlook for babies with non-mosaic trisomy 22 is uniformly poor and prolonged survival unusual. Survival has been associated in the past with undetected mosaicism (Bacino et al, 1995), unbalanced 11 : 22 or Robertsonian 22 : 22 translocation (Lalchev et al, 1978 Schinzel, 1981Schinzel, , 1984Voiculescu et al, 1987), placental mosaicism (Kalousek et al, 1989), and uniparental disomy (Balmer et al, 1999). However, the use of high-resolution cytogenetics and or fluorescence in situ hybridization (FISH) has confirmed survival of true nonmosaic trisomy 22 into the third trimester and beyond (Stratton et al, 1993;Bacino et al, 1995).…”

Prenatal diagnosis of partial trisomy 22 derived from a maternal t(11;22) (q23;q11).

“…Other signs of 22 trisomy included renal aplasia, low-set nipples, criporchidism, craniofacial asymmetry, inguinal hernia, and strabismus (Penchaszadeh and Coco 1975; Vianello and Bonioli 1975;Emanuel et al 1976). No difference in distribution between the sexes was found in trisomy 22 cases (Lalchev et al 1978). …”