Appendix 1 Group 1: phenotypically unaffected parents with the same unbalanced chromosome abnormality as their unaffected children
| Region | Size | Con | Ascertainment | Mode | C | Ref | |
|---|---|---|---|---|---|---|---|
| Entries in italics are abstracts only. Con, confirmed with FISH and/or CGH (F); chromosome paint (P); molecular (M) or biochemical analysis (B); C, number of carriers in family; PD, prenatal diagnosis; PA, phenotypic abnormality; PA*, phenotypic abnormality due to another identified cause; MC, miscarriage; I, infertility; Mat, maternal; Pat, paternal; Both, maternal and paternal transmission; N, Not transmitted from an unbalanced parent; m, mosaic. | |||||||
| del | |||||||
| 2 | p12-p12 | 6.1 | F,M | PD Previous +18 | Mat | 5 | Family 11 |
| 2 | p12-p12 | 6.9 | F,M | PD Maternal age | Both | 3 | Family 21 |
| 2 | q13-q14.1 | 6.0 | F | MC Miscarriages | Mat | 2 | 2 |
| 3 | p25.3-pter | 10.1 | F | PD Maternal age | Mat | 2 | 3 |
| 5 | p14-p14 | 13.8 | M | PD Maternal age | Mat | 6 | 4 |
| 8 | p23.1/2-pter | 6.1 | F | PD Maternal age | Pat | 2 | 5 |
| 8 | q24.13q24.22 | 4.2 | P,F | PD Triple screen | Mat | 2 | 6 |
| 9 | p21.2-p22.1 | 7.6 | – | PD Maternal age | Both | 3 | 7 |
| 10 | q11.2q21.2 | 13.3 | P | MC Miscarriages | N | 1 | 158 |
| 11 | p12 | 6.1 | – | PD Maternal age | Mat | 3 | 8 |
| 13 | q21-q21 | 16.0 | – | MC Miscarriages | Mat | 2 | 9 |
| 16 | q13q22 | 7.0 | F | PD Maternal age | Mat | 3 | 10 |
| 16 | q21-q21 | 7.0 | M | PD Maternal age | Pat | 3 | 11 |
| 18 | p11.31-pter | 4.4 | – | PD Serum AFP | Pat | 2 | 12 |
| Av 8.2 | |||||||
| dup | |||||||
| 1 | p21-p31 | 31.3 | F | PD Maternal age | Mat | 2 | 13 |
| 3 | q28-q29 | 8.6 | P | PD Maternal age | Pat | 3 | 12 |
| 8 | p23.1-p23.3 | 6.1 | F | I Oligoasthenospermia | Mat | 3 | 14 |
| 8 | p22 | 3.4 | F | PD Triple screen | Both | 3 | 15 |
| 10 | p13-p14 | 5.3 | F | PD Low serum screen | Mat | 3 | 16 |
| 13 | q14-q21 | 18.3 | F | PD Maternal hyposomia | Mat | 2 | 17 |
| 18 | p11.2-pter | 22.0 | M | PD Raised seurm AFP | Mat | 2 | 18 |
| Av 13.6 | |||||||
| der | |||||||
| der(5) | dup(9)(p12-p21.3) | 21.0 | P,F | PA*Phenotype of daughter | N | 1 | 159 |
| ins(5;9) | |||||||
| der(20) | dup(13)(q13-q14.3) | 11.6 | B | PA* Phenotype of sibling | N | 1 | 160 |
| ins(20;13) | |||||||
| der(18) | dup(18)(q11.2q12.2) | 10.0 | F | PD FH Down’s syndrome | N | 1 | 161 |
| ins(18;18) | |||||||
| der(1) | del 1p32-pter dup? | 48.5 | – | PD Maternal age | Pat | 2 | 19 |
| t(1;?) | |||||||
| der(6) | del ?6p25-pter & >?21q11-pter | – | – | PA* Phenotype of sibling | Mat | 4 | 20 |
| t(6;21) | |||||||
| der(9) | del 22q11.21-pter | 4.1 | F | PD Maternal age | Mat | 4 | 21 |
| t(9;22) | (9q subtel intact) | 0.0 | |||||
| Totals | 27 families | 21/27 | PD 20/27; MC 3/27; PA* 3/27; I 1/23 | Mat 15/23; >pat 5/23; >both 3/23 | 70 | 8 Abstract only | |