1q21.1 duplication syndrome
1q21.1 duplication syndrome or 1q21.1 (recurrent) microduplication is a rare aberration of chromosome 1.
| 1q21.1 duplication syndrome | |
|---|---|
| Other names | 1q21.1 (recurrent) microduplication |
| 1q21.1 duplication syndrome is inherited in an autosomal dominant manner | |
| Specialty | Medical genetics |
On chromosome 1, a human cell typically has one pair of identical chromosomes. One copy of chromosome 1 in the 1q21.1 duplication syndrome is overcomplete because a portion of its sequence has been duplicated twice or more. The letters 1q21.1 stand for chromosome 1, q for the long arm of the chromosome, and 21.1 for the portion of the long arm that contains the duplication.
Next to the duplication syndrome, there is also a 1q21.1 deletion syndrome. While there are two or three copies of a similar part of the DNA on a particular spot with the duplication syndrome, there is a part of the DNA missing with the deletion syndrome on the same spot. Literature refers to both the deletion and the duplication as the 1q21.1 copy-number variations (CNV).
The CNV leads to a very variable phenotype and the manifestations in individuals are quite variable. Some people who have the syndrome can function in a normal way, while others have symptoms of developmental delays and various physical anomalies.