Accueil
chromosome 15 en cours de trad'
Le chromosome 15 est l'une des 23 paires de chromosomes chez l'être humain.
Dans un cas normal, nous avons tous 2 copies de ce chromosome 15. Une copie qui nous vient de notre père, et l'autre de notre mère.
Identifier les gènes sur chaque chromosome, est l'une des principales tâches de la recherche génétique à ce jour.
Les chercheurs utilisant des approches diférentes pour établir le nombre de gènes dans chaque chromosome, le nombre estimatif de chaque gène peut varier.
Le chromosome 15 contient entre 700 et 900 gènes.
Genes
Les gènes suivant ont été localisés sur le chromosome 15 :
FAH: fumarylacetoacetate hydrolase (fumarylacetoacetase)
FBN1: fibrillin 1 (Marfan syndrome)
HEXA: hexosaminidase A (alpha polypeptide)
IVD: isovaleryl Coenzyme A dehydrogenase
OCA2: oculocutaneous albinism II (pink-eye dilution homolog, mouse)
RAD51: RAD51 homolog (RecA homolog, E. coli) (S. cerevisiae)
STRC: stereocilin
UBE3A: ubiquitin protein ligase E3A (human papilloma virus E6-associated protein, Angelman syndrome)
PML: promyelocytic leukemia protein (involved in t(15,17) with RARalpha, predominant cause of acute promyelocytic leukemia.
Maladies :
Les maladies suivantes ont été rattachées à une anomalie sur le chromosme 15
Angelman syndrome
Prader-Willi syndrome
Les troubles suivants sont causés par des changements dans la structure ou le nombre de copies du chromosme 15 :
Le syndrome d'Angelman résulte d'une perte génétique dans la région critique du chromosome 15 : la région 15q11q13. Cette région contient un gène appelé UBE3A, qui quand il mute ou est absent, cause la plus grande partie des troubles. Le nombre normal de copies du gène UBE3A est de deux, une de chaque parent. Ces deux copies sont actives dans beaucoup de tissus du corps. Dans le cerveau, seule une copie héritée de la maman est active.
Si la copie maternelle est manquante à cause d'une abbération chromosomique, le patient n'aura pas de copie efficace du gène UBE3A au niveau du cerveau.
Dans la majeure partie des cas (plus de 70%) les personnes souffrant du syndrome d'Angelman présente une délétion de la copie maternelle du chromosome 15.
SUITE PLUS TARD...
In most cases (about 70%), people with Angelman syndrome have a deletion in the maternal copy of chromosome 15. This chromosomal change deletes the region of chromosome 15 that includes the UBE3A gene. Because the copy of the UBE3A gene inherited from a person's father (the paternal copy) is normally inactive in the brain, a deletion in the maternal chromosome 15 results in no active copies of the UBE3A gene in the brain.
In 3% to 7% of cases, Angelman syndrome occurs when a person has two copies of the paternal chromosome 15 instead of one copy from each parent. This phenomenon is called paternal uniparental disomy (UPD). People with paternal UPD for chromosome 15 have two copies of the UBE3A gene, but they are both inherited from the father and are therefore inactive in the brain.
About 10% of Angelman syndrome cases are caused by a mutation in the UBE3A gene, and another 3% result from a defect in the DNA region that controls the activation of the UBE3A gene and other genes on the maternal copy of chromosome 15. In a small percentage of cases, Angelman syndrome may be caused by a chromosomal rearrangement called a translocation or by a mutation in a gene other than UBE3A. These genetic changes can abnormally inactivate the UBE3A gene.
Prader-Willi syndrome: Prader-Willi syndrome is caused by the loss of active genes in a specific part of chromosome 15, the 15q11-q13 region. People normally have two copies of this chromosome in each cell, one copy from each parent. Prader-Willi syndrome occurs when the paternal copy is partly or entirely missing. Researchers are working to identify genes on chromosome 15 that are responsible for the characteristic features of Prader-Willi syndrome.
In about 70% of cases, Prader-Willi syndrome occurs when the 15q11-q13 region of the paternal chromosome 15 is deleted. The genes in this region are normally active on the paternal copy of the chromosome and are inactive on the maternal copy. Therefore, a person with a deletion in the paternal chromosome 15 will have no active genes in this region.
In about 25% of cases, a person with Prader-Willi syndrome has two maternal copies of chromosome 15 in each cell instead of one copy from each parent. This phenomenon is called maternal uniparental disomy. Because some genes are normally active only on the paternal copy of this chromosome, a person with two maternal copies of chromosome 15 will have no active copies of these genes.
In a small percentage of cases, Prader-Willi syndrome is caused by a chromosomal rearrangement called a translocation. Rarely, the condition is caused by an abnormality in the DNA region that controls the activity of genes on the paternal chromosome 15.
Other chromosomal conditions: A specific chromosomal change called an isodicentric chromosome 15 (previously called an inverted duplication 15) can affect growth and development. This small extra chromosome is made up of genetic material from chromosome 15 that has been abnormally duplicated (copied) and attached end-to-end. In some cases, the extra chromosome is very small and has no effect on a person's health. A larger isodicentric chromosome 15 can result in weak muscle tone (hypotonia), mental retardation, seizures, and behavioral problems. Signs and symptoms of autism (a developmental disorder that affects communication and social interaction) have also been associated with the presence of an isodicentric chromosome 15.
Other changes in the number or structure of chromosome 15 can cause mental retardation, delayed growth and development, hypotonia, and characteristic facial features. These changes include an extra copy of part of chromosome 15 in each cell (partial trisomy 15) or a missing segment of the chromosome in each cell (partial monosomy 15). In some cases, several of the chromosome's DNA building blocks (nucleotides) are deleted or duplicated.
References
Bittel DC, Butler MG (2005). "Prader-Willi syndrome: clinical genetics, cytogenetics and molecular biology". Expert Rev Mol Med 7 (14): 1-20. PMID 16038620.
Bittel DC, Kibiryeva N, Talebizadeh Z, Butler MG (2003). "Microarray analysis of gene/transcript expression in Prader-Willi syndrome: deletion versus UPD". J Med Genet 40 (
: 568-74. PMID 12920063.
Bittel DC, Kibiryeva N, Talebizadeh Z, Driscoll DJ, Butler MG (2005). "Microarray analysis of gene/transcript expression in Angelman syndrome: deletion versus UPD". Genomics 85 (1): 85-91. PMID 15607424.
Borgatti R, Piccinelli P, Passoni D, Dalpra L, Miozzo M, Micheli R, Gagliardi C, Balottin U (2001). "Relationship between clinical and genetic features in "inverted duplicated chromosome 15" patients". Pediatr Neurol 24 (2): 111-6. PMID 11275459.
Butler MG, Bittel DC, Kibiryeva N, Talebizadeh Z, Thompson T (2004). "Behavioral differences among subjects with Prader-Willi syndrome and type I or type II deletion and maternal disomy". Pediatrics 113 (3 Pt 1): 565-73. PMID 14993551.
Cassidy SB, Dykens E, Williams CA (2000). "Prader-Willi and Angelman syndromes: sister imprinted disorders". Am J Med Genet 97 (2): 136-46. PMID 11180221.
Clayton-Smith J, Laan L (2003). "Angelman syndrome: a review of the clinical and genetic aspects". J Med Genet 40 (2): 87-95. PMID 12566516.
Gilbert F (1999). "Disease genes and chromosomes: disease maps of the human genome. Chromosome 15". Genet Test 3 (3): 309-22. PMID 10495933.
Lee S, Wevrick R (2000). "Identification of novel imprinted transcripts in the Prader-Willi syndrome and Angelman syndrome deletion region: further evidence for regional imprinting control". Am J Hum Genet 66 (3): 848-58. PMID 10712201.
Rineer S, Finucane B, Simon EW (1998). "Autistic symptoms among children and young adults with isodicentric chromosome 15". Am J Med Genet 81 (5): 428-33. PMID 9754629.
Zollino M, Tiziano F, Di Stefano C, Neri G (1999). "Partial duplication of the long arm of chromosome 15: confirmation of a causative role in craniosynostosis and definition of a 15q25-qter trisomy syndrome". Am J Med Genet 87 (5): 391-4. PMID 10594876.
[b]Wikipedia[i]
Le chromosome 15 est l'une des 23 paires de chromosomes chez l'être humain.
Dans un cas normal, nous avons tous 2 copies de ce chromosome 15. Une copie qui nous vient de notre père, et l'autre de notre mère.
Identifier les gènes sur chaque chromosome, est l'une des principales tâches de la recherche génétique à ce jour.
Les chercheurs utilisant des approches diférentes pour établir le nombre de gènes dans chaque chromosome, le nombre estimatif de chaque gène peut varier.
Le chromosome 15 contient entre 700 et 900 gènes.
Genes
Les gènes suivant ont été localisés sur le chromosome 15 :
FAH: fumarylacetoacetate hydrolase (fumarylacetoacetase)
FBN1: fibrillin 1 (Marfan syndrome)
HEXA: hexosaminidase A (alpha polypeptide)
IVD: isovaleryl Coenzyme A dehydrogenase
OCA2: oculocutaneous albinism II (pink-eye dilution homolog, mouse)
RAD51: RAD51 homolog (RecA homolog, E. coli) (S. cerevisiae)
STRC: stereocilin
UBE3A: ubiquitin protein ligase E3A (human papilloma virus E6-associated protein, Angelman syndrome)
PML: promyelocytic leukemia protein (involved in t(15,17) with RARalpha, predominant cause of acute promyelocytic leukemia.
Maladies :
Les maladies suivantes ont été rattachées à une anomalie sur le chromosme 15
Angelman syndrome
Prader-Willi syndrome
Les troubles suivants sont causés par des changements dans la structure ou le nombre de copies du chromosme 15 :
Le syndrome d'Angelman résulte d'une perte génétique dans la région critique du chromosome 15 : la région 15q11q13. Cette région contient un gène appelé UBE3A, qui quand il mute ou est absent, cause la plus grande partie des troubles. Le nombre normal de copies du gène UBE3A est de deux, une de chaque parent. Ces deux copies sont actives dans beaucoup de tissus du corps. Dans le cerveau, seule une copie héritée de la maman est active.
Si la copie maternelle est manquante à cause d'une abbération chromosomique, le patient n'aura pas de copie efficace du gène UBE3A au niveau du cerveau.
Dans la majeure partie des cas (plus de 70%) les personnes souffrant du syndrome d'Angelman présente une délétion de la copie maternelle du chromosome 15.
SUITE PLUS TARD...
In most cases (about 70%), people with Angelman syndrome have a deletion in the maternal copy of chromosome 15. This chromosomal change deletes the region of chromosome 15 that includes the UBE3A gene. Because the copy of the UBE3A gene inherited from a person's father (the paternal copy) is normally inactive in the brain, a deletion in the maternal chromosome 15 results in no active copies of the UBE3A gene in the brain.
In 3% to 7% of cases, Angelman syndrome occurs when a person has two copies of the paternal chromosome 15 instead of one copy from each parent. This phenomenon is called paternal uniparental disomy (UPD). People with paternal UPD for chromosome 15 have two copies of the UBE3A gene, but they are both inherited from the father and are therefore inactive in the brain.
About 10% of Angelman syndrome cases are caused by a mutation in the UBE3A gene, and another 3% result from a defect in the DNA region that controls the activation of the UBE3A gene and other genes on the maternal copy of chromosome 15. In a small percentage of cases, Angelman syndrome may be caused by a chromosomal rearrangement called a translocation or by a mutation in a gene other than UBE3A. These genetic changes can abnormally inactivate the UBE3A gene.
Prader-Willi syndrome: Prader-Willi syndrome is caused by the loss of active genes in a specific part of chromosome 15, the 15q11-q13 region. People normally have two copies of this chromosome in each cell, one copy from each parent. Prader-Willi syndrome occurs when the paternal copy is partly or entirely missing. Researchers are working to identify genes on chromosome 15 that are responsible for the characteristic features of Prader-Willi syndrome.
In about 70% of cases, Prader-Willi syndrome occurs when the 15q11-q13 region of the paternal chromosome 15 is deleted. The genes in this region are normally active on the paternal copy of the chromosome and are inactive on the maternal copy. Therefore, a person with a deletion in the paternal chromosome 15 will have no active genes in this region.
In about 25% of cases, a person with Prader-Willi syndrome has two maternal copies of chromosome 15 in each cell instead of one copy from each parent. This phenomenon is called maternal uniparental disomy. Because some genes are normally active only on the paternal copy of this chromosome, a person with two maternal copies of chromosome 15 will have no active copies of these genes.
In a small percentage of cases, Prader-Willi syndrome is caused by a chromosomal rearrangement called a translocation. Rarely, the condition is caused by an abnormality in the DNA region that controls the activity of genes on the paternal chromosome 15.
Other chromosomal conditions: A specific chromosomal change called an isodicentric chromosome 15 (previously called an inverted duplication 15) can affect growth and development. This small extra chromosome is made up of genetic material from chromosome 15 that has been abnormally duplicated (copied) and attached end-to-end. In some cases, the extra chromosome is very small and has no effect on a person's health. A larger isodicentric chromosome 15 can result in weak muscle tone (hypotonia), mental retardation, seizures, and behavioral problems. Signs and symptoms of autism (a developmental disorder that affects communication and social interaction) have also been associated with the presence of an isodicentric chromosome 15.
Other changes in the number or structure of chromosome 15 can cause mental retardation, delayed growth and development, hypotonia, and characteristic facial features. These changes include an extra copy of part of chromosome 15 in each cell (partial trisomy 15) or a missing segment of the chromosome in each cell (partial monosomy 15). In some cases, several of the chromosome's DNA building blocks (nucleotides) are deleted or duplicated.
References
Bittel DC, Butler MG (2005). "Prader-Willi syndrome: clinical genetics, cytogenetics and molecular biology". Expert Rev Mol Med 7 (14): 1-20. PMID 16038620.
Bittel DC, Kibiryeva N, Talebizadeh Z, Butler MG (2003). "Microarray analysis of gene/transcript expression in Prader-Willi syndrome: deletion versus UPD". J Med Genet 40 (
: 568-74. PMID 12920063. Bittel DC, Kibiryeva N, Talebizadeh Z, Driscoll DJ, Butler MG (2005). "Microarray analysis of gene/transcript expression in Angelman syndrome: deletion versus UPD". Genomics 85 (1): 85-91. PMID 15607424.
Borgatti R, Piccinelli P, Passoni D, Dalpra L, Miozzo M, Micheli R, Gagliardi C, Balottin U (2001). "Relationship between clinical and genetic features in "inverted duplicated chromosome 15" patients". Pediatr Neurol 24 (2): 111-6. PMID 11275459.
Butler MG, Bittel DC, Kibiryeva N, Talebizadeh Z, Thompson T (2004). "Behavioral differences among subjects with Prader-Willi syndrome and type I or type II deletion and maternal disomy". Pediatrics 113 (3 Pt 1): 565-73. PMID 14993551.
Cassidy SB, Dykens E, Williams CA (2000). "Prader-Willi and Angelman syndromes: sister imprinted disorders". Am J Med Genet 97 (2): 136-46. PMID 11180221.
Clayton-Smith J, Laan L (2003). "Angelman syndrome: a review of the clinical and genetic aspects". J Med Genet 40 (2): 87-95. PMID 12566516.
Gilbert F (1999). "Disease genes and chromosomes: disease maps of the human genome. Chromosome 15". Genet Test 3 (3): 309-22. PMID 10495933.
Lee S, Wevrick R (2000). "Identification of novel imprinted transcripts in the Prader-Willi syndrome and Angelman syndrome deletion region: further evidence for regional imprinting control". Am J Hum Genet 66 (3): 848-58. PMID 10712201.
Rineer S, Finucane B, Simon EW (1998). "Autistic symptoms among children and young adults with isodicentric chromosome 15". Am J Med Genet 81 (5): 428-33. PMID 9754629.
Zollino M, Tiziano F, Di Stefano C, Neri G (1999). "Partial duplication of the long arm of chromosome 15: confirmation of a causative role in craniosynostosis and definition of a 15q25-qter trisomy syndrome". Am J Med Genet 87 (5): 391-4. PMID 10594876.
[b]Wikipedia[i]
