Table 1.
Sequence Duplications and Consequences
| Duplication | Location | Consequences |
| Glucocerebrosidase gene | 1q21 | Gaucher disease |
| 3.3-kb repeats | 4q35 | 1. facioscapulohumeral muscular dystrophy? |
| 2. polymorphic copy number | ||
| SMA gene | 5q11.2–q13.3 | spinal muscular atrophy |
| 21-hydroxyase and complement 4 genes | 6p21.3 | adrenal hyperplasia III (21-hydroxylase deficiency) |
| GTF2Igene | 7q11.23 | William’s syndrome |
| CYP11B2 andCYP11B1 genes | 8q21 | glucocorticoid-remediable aldosteronism |
| β and β-like genes | 11p15.5 | β-thalassemia |
| Homologous sequences? | 15q11–q13 | Prader-Willi and Angelman syndromes |
| Subtelomeric repeats | 16pter | trisomy of chromosome 16? |
| α gene | 16p13.3 | α-thalassemia |
| PKD1gene | 16p13.1 | complicates the analysis of polycystic kidney disease 1 patients |
| 17-kb repeats | 17p11.2–p12 | Charcot-Marie-tooth type 1A |
| 200 kb repeats (gene cluster) | 17p11.2 | Smith-Magenis syndrome |
| Low copy repeats? | 22q11 | DiGeorge syndrome |
| Velocardiofacial syndrome | ||
| CYP2D6 gene | 22q13.1 | debrisoquine metabolism deficiency |
| Homologous sequences? | Xp21.3 | dosage-sensitive sex reversal |
| Homologous sequences | Xp22.32 | X-linked ichthyosis |
| Homologous sequences? | Xq22 | Pelizaeus-Merzbacher disease |
| Homologous sequences | Xq25 | lymphoproliferative disorder? |
| Iduronate-2-sulphatase gene | Xq28 | Hunter’s syndrome |
| Red and Green pigment genes | Xq28 | 1. color blindness |
| 2. polymorphic copy number | ||
| 11.3-kb inverted repeats | Xq28 | 1. Emery-Dreifuss syndrome |
| 2. polymorphic inversion of 38 kb | ||
| 9.5-kb repeats | Xq28 | hemophilia A |
| 13-bp repeats | mitochondria | Kearns-Sayre syndrome |
