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| 1q21.1 duplication syndrome | |
|---|---|
| Other names | 1q21.1 (recurrent) microduplication |
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| 1q21.1 duplication syndrome is: inherited in an autosomal dominant manner | |
| Specialty | Medical genetics  |
1q21.1 duplication syndrome/1q21.1 (recurrent) microduplication is a rare aberration of chromosome 1.
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.
Symptoms and signs※
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Cause※
Due to this genetic misprint the embryo may experience problems in the development during the first months of pregnancy. Approximately 20 to 40 days after fertilization, something goes wrong in the construction of the body parts and brain, which leads to a chain reaction.
Structure of 1q21.1※
Diagnostics※
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Research※
Statistical research showed that schizophrenia is significantly more common in combination with 1q21.1 deletion syndrome. On the other side, autism is significantly more common with 1q21.1 duplication syndrome. Similar observations were done for chromosome 16 on 16p11.2 (deletion: autism/duplication: schizophrenia), chromosome 22 on 22q11.21 (deletion (Velo-cardio-facial syndrome): schizophrenia/duplication: autism) and 22q13.3 (deletion (Phelan-McDermid syndrome): schizophrenia/duplication: autism). Further research confirmed that the odds on a relation between schizophrenia and deletions at 1q21.1, 3q29, 15q13.3, 22q11.21 en Neurexin 1 (NRXN1) and duplications at 16p11.2 are at 7.5% or higher.
Common variations in the BCL9 gene, which is in the distal area, confer risk of schizophrenia and may also be associated with bipolar disorder and major depressive disorder.
Research is done on 10-12 genes on 1q21.1 that produce DUF1220-locations. DUF1220 is an unknown protein, which is active in the neurons of the brain near the neocortex. Based on research on apes and other mammals, it is assumed that DUF1220 is related to cognitive development (man: 212 locations; chimpanzee: 37 locations; monkey: 30 locations; mouse: 1 location). It appears that the DUF1220-locations on 1q21.1 are in areas that are related to the size and the development of the brain. The aspect of the size and development of the brain is related to autism (macrocephaly) and schizophrenia (microcephaly). It is assumed that a deletion or a duplication of a gene that produces DUF1220-areas might cause growth and development disorders in the brain
Another relation between macrocephaly with duplications and microcephaly with deletions has been seen in research on the HYDIN Paralog or HYDIN2. This part of 1q21.1 is involved in the development of the brain. It is assumed to be a dosage-sensitive gene. When this gene is not available in the 1q21.1 area it leads to microcephaly. HYDIN2 is a recent duplication (found only in humans) of the HYDIN gene found on 16q22.2.
GJA5 has been identified as the gene that is responsible for the phenotypes observed with congenital heart diseases on the 1q21.1 location. In case of a duplication of GJA5 tetralogy of Fallot is more common. In case of a deletion other congenital heart diseases than tetralogy of Fallot are more common.
References※
- ^ A. Ploeger; 'Towards an integration of evolutionary psychology and developmental science: New insights from evolutionary developmental biology'
- ^ Levinson DF, Duan J, Oh S, et al. (March 2011). "Copy number variants in schizophrenia: confirmation of five previous findings and new evidence for 3q29 microdeletions and VIPR2 duplications". Am J Psychiatry. 168 (3): 302–16. doi:10.1176/appi.ajp.2010.10060876. PMC 4441324. PMID 21285140.
- ^ Ikeda M, Aleksic B, Kirov G, et al. (February 2010). "Copy number variation in schizophrenia in the Japanese population". Biol. Psychiatry. 67 (3): 283–6. doi:10.1016/j.biopsych.2009.08.034. PMID 19880096. S2CID 26047827.
- ^ Li J, Zhou G, Ji W, et al. (March 2011). "Common variants in the BCL9 gene conferring risk of schizophrenia". Arch. Gen. Psychiatry. 68 (3): 232–40. doi:10.1001/archgenpsychiatry.2011.1. PMID 21383261.
- ^ Dumas L, Sikela JM (2009). "DUF1220 domains, cognitive disease, and human brain evolution". Cold Spring Harb. Symp. Quant. Biol. 74: 375–82. doi:10.1101/sqb.2009.74.025. PMC 2902282. PMID 19850849.
- ^ Doggett NA, Xie G, Meincke LJ, et al. (Dec 2006). "A 360-kb interchromosomal duplication of the human HYDIN locus". Genomics. 88 (6): 762–71. doi:10.1016/j.ygeno.2006.07.012. PMID 16938426.
- ^ Soemedi, R.; et al. (2011). "Phenotype-Specific Effect of Chromosome 1q21.1 Rearrangements and GJA5 Duplications in 2436 Congenital Heart Disease Patients and 6760 Controls". Hum. Mol. Genet. 21 (7): 1513–1520. doi:10.1093/hmg/ddr589. PMC 3298277. PMID 22199024.
Further reading※
- Mefford HC, Sharp AJ, Baker C, et al. (October 2008). "Recurrent rearrangements of chromosome 1q21.1 and variable pediatric phenotypes". N. Engl. J. Med. 359 (16): 1685–99. doi:10.1056/NEJMoa0805384. PMC 2703742. PMID 18784092.
- Brunetti-Pierri N, Berg JS, Scaglia F, et al. (December 2008). "Recurrent reciprocal 1q21.1 deletions and duplications associated with microcephaly or macrocephaly and developmental and behavioral abnormalities". Nat. Genet. 40 (12): 1466–71. doi:10.1038/ng.279. PMC 2680128. PMID 19029900.
- Crespi B, Stead P, Elliot M (January 2010). "Evolution in health and medicine Sackler colloquium: Comparative genomics of autism and schizophrenia". Proc. Natl. Acad. Sci. U.S.A. 107 (Suppl 1): 1736–41. Bibcode:2010PNAS..107.1736C. doi:10.1073/pnas.0906080106. PMC 2868282. PMID 19955444.