Choose Your Language
Home  /  Futurs Parents  /  Information sur les statuts génétiques

Information sur les statuts génétiques

Trisomies

La trisomie est un statut génétique dans lequel il existe trois chromosomes au lieu de la paire chromosomique habituelle.

Trisomie 21 / Syndrome de Down:

La trisomie 21, plus communément connue sous le nom de syndrome de Down, est un statut génétique causé par la présence d’une copie supplémentaire du chromosome 21. Malheureusement, une fausse couche se produit dans 30 % des grossesses présentant un syndrome de Down. Les enfants qui naissent porteurs d’un syndrome de Down nécessitent des soins extra médicaux qui dépendent des problèmes de santé propres à chaque enfant. La plupart des enfants présentant un syndrome de Down ont des incapacités intellectuelles légères à modérées. Les interventions précoces s’avèrent essentielles pour permettre aux individus atteints du syndrome de Down de mener une vie saine et productive. Pour davantage d’informations ou d’aide, consultez notre page de renseignements et de références.

Trisomie 18 / Syndrome d’Edwards:

La trisomie 18, ou syndrome d’Edwards, se produit lorsque l’enfant a trois copies du chromosome 18, au lieu de deux. Malheureusement, les grossesses présentant un syndrome d’Edwards ont un risque élevé de fausse couche, et la plupart des bébés naissant avec un syndrome d’Edwards meurent dans les premières semaines de leur vie ; seuls moins de 10 % d’entre eux vivent au-delà de la première année. Les nourrissons porteurs d’un syndrome d’Edwards présentent de graves incapacités intellectuelles. Des anomalies congénitales concernent habituellement le cœur, le cerveau et les reins. Les anomalies physiques comportent un bec de lièvre avec fentes labiale et palatine, une petite tête, des pieds bots, des doigts sous-développés et une petite mâchoire.

Trisomie 13 / Syndrome de Patau:

La trisomie 13, ou syndrome de Patau, se produit lorsque le bébé a trois copies du chromosome 13, au lieu de deux. Malheureusement, les grossesses diagnostiquées syndrome de Patau, ont un risque élevé de fausse couche et de décès à la naissance. La plupart des bébés nés avec un syndrome de Patau ne survivent pas au-delà de quelques semaines. Ils peuvent avoir des anomalies cardiaques, cérébrales ou de la moelle épinière, des doigts et/ou des orteils surnuméraires, une fente labiale avec ou sans fente palatine, et des muscles hypotoniques. De nombreux bébés ont également des anomalies congénitales d’autres organes.

Deletion Syndromes

Deletion syndromes are defined as a group of clinically recognisable disorders characterised by a small deletion of a chromosomal segment. The size and position of the deletion determine which clinical features are manifested and how severe they are.

5p / Cri-du-Chat:

Also known as 5P deletion sydnrome, babies typically exhibit small head size, low birth weight, decreased muscle tone. and have moderate to severe intellectual disability. Feeding and/or breathing difficulties are also common.

1p36:

Babies born with 1p36 deletion syndrome typically have weak muscle tone, heart and other organ defects. Most will display developmental problems and varying degrees of intellectual disability.

2q33.1:

Babies born with 2q33.1 will typically experience delayed growth and exhibit behavioural developmental problems. Severe feeding difficulties are common and the incidence of cleft palate is also high.

Sex Chromosomal Aneuploidy

Each cell in your body contains 46 chromosomes arranged in 23 pairs. One of these chromosome pairs is known as the sex chromosomes because this pair of chromosomes determines our sex. Sex chromosome abnormalities occur when there are extra, missing, or altered sex chromosomes present.

XXY / Klinefelter Syndrome:

Klinefelter’s syndrome is a genetic condition that only affects males. Affected males have an extra X chromosome.Males with Klinefelter’s syndrome have small testes which do not produce enough of the male hormone testosterone before birth and during puberty. This lack of testosterone means that during puberty, the normal male sexual characteristics do not develop fully. There is reduced facial and pubic hair, and some breast tissue often develops. The lack of testosterone is also responsible for other symptoms, including infertility.

X / Turner Syndrome:

Turner syndrome is caused by a completely or partially missing X sex chromosome in females. Females with Turner syndrome often have a wide range of symptoms and some distinctive characteristics. Two that occur in almost all cases of Turner syndrome are:
-being shorter than average
-underdeveloped ovaries (female reproductive organs), resulting in a lack of monthly periods and infertility.

XXX / Triple X:

Triple X syndrome, also called trisomy X is characterized by the presence of an additional X chromosome in each of a female’s cells. The symptoms and physical features associated with trisomy X vary greatly from one person to another. Some females may have no symptoms (asymptomatic) or very mild symptoms and may go undiagnosed. Other women may have a wide variety of different abnormalities.
Triple X syndrome is associated with an increased risk of learning disabilities and delayed development of speech and language skills. Delayed development of motor skills (such as sitting and walking), weak muscle tone (hypotonia), and behavioral and emotional difficulties are also possible, but these characteristics vary widely among affected girls and women. Seizures or kidney abnormalities occur in about 10 percent of affected females.

XYY / Jacob Syndrome:

XYY, sometime called Jacob syndrome, affects only males and is caused by the presence of an extra Y chromosome.
Affected individuals are usually very tall. Many experience severe acne during adolescence. Additional symptoms may include learning disabilities and behavioural problems such as impulsivity.