Karyotypes of cases with tetrasomy 21 and tetrasomy 21 mosaicism
| Karyotype | Jabs et al11 | Daumer-Haas et al10 |
Nagarsheth and Mootabar18 | Gutiérrez-Angulo et al12 | Cerretini et al13 | Our patient |
| Mosaic/non-mosaic | Non-mosaic | Non-mosaic | Mosiac | Non-mosaic | Non-mosaic | Non-mosaic |
| Peripheral blood lymphocytes | 48,XY,+21,+21 | 47,XX,+idic(21)(q22.1) | Mos47,XY,+mar.ish i(21)(q10)[1 cell]/ 46,XY[119 cells] | 47,XY,+psu idic(21)(q22.1) | 47,XY,+psu dic(21;21) (q22.11;q22.11) | 47,XY,+psu idic(21)(q22.1) |
| Skin fibroblasts | 47,XY,+psu idic(21)(q22.1) | |||||
| Amniocytes | Mos47,XY, +i(21q)/46,XY | |||||
| Parental chromosomes | Normal | Maternal studies normal | Normal | Normal | Normal | Normal |