What is the cause of duplication syndrome?
MECP2 duplication syndrome is caused by a genetic abnormality in which a portion of the X chromosome appears two times on one of the X chromosomes (duplication) instead of once. By definition, the affected region always contains the methyl-CpG-binding protein 2 (MECP2) gene.
How is 7q11 23 duplication diagnosed?
Diagnosis/testing. The diagnosis of 7q11. 23 duplication syndrome is established by detection of a recurrent 1.5- to 1.8-Mb heterozygous duplication of the Williams-Beuren syndrome critical region.
What is chromosome 7q11 23?
Merla G, Brunetti-Pierri N, Micale L, Fusco C. Copy number variants at Williams-Beuren syndrome 7q11.23 region. Hum Genet. 2010 Jul;128(1):3-26. doi: 10.1007/s00439-010-0827-2.
Can duplication syndrome be inherited?
In most cases, MECP2 duplication syndrome is inherited from a mother who carries the duplication but has no symptoms. Rarely, the condition is not inherited. In these cases it may occur randomly during the formation of the egg or sperm, or shortly after the egg and sperm join together.
What are the symptoms of duplication?
What are the signs and symptoms of MECP2 duplication syndrome?
- Hypotonia (low muscle tone), which is usually apparent in infancy.
- Delayed development of milestones.
- Moderate to severe intellectual disability.
- Inability to talk, or limited speech ability that may be lost with age.
Can you have less than 23 chromosomes?
Monosomy means that a person is missing one chromosome in the pair. Instead of 46 chromosomes, the person has only 45 chromosomes. This means a girl with TS has only one X chromosome in her 23 rd pair. Sometimes an error occurs when an egg or sperm cell is forming.
How often does MECP2 duplication syndrome occur?
The prevalence of MECP2 duplication syndrome is unknown; more than 200 affected individuals have been described in the scientific literature. It is estimated that this condition is responsible for 1 to 2 percent of all cases of intellectual disability caused by changes in the X chromosome.
Can people with Williams syndrome lead a normal life?
Living with Williams Syndrome Every child with Williams syndrome is different. Some can lead a very normal life. Others have more serious health and learning problems. They may need lifelong medical care.
What diseases are caused by duplication mutations?
Deletions, Duplications, and Disease
| Genetic Disease | Type of Rearrangement | Location Affected |
|---|---|---|
| Charcot-Marie-Tooth disease type I | Duplication | 17p12 |
| Hereditary neuropathy with pressure palsies | Deletion | 17p12 |
| Smith-Magenis syndrome | Deletion | 17p11.2 |
| Williams-Beuren syndrome | Deletion | 7q11.23 |