What is Robertsonian translocation Down syndrome?

The Robertsonian translocation is unbalanced and the baby has three copies of the long arm of chromosome 21 instead of two. This causes a type of Down’s syndrome called translocation Down’s syndrome. The effects on the baby are exactly the same as when Down’s syndrome is caused by having an extra entire chromosome 21.

What is Robertsonian translocation karyotype?

In Robertsonian translocation, the pericentric regions of two acrocentric chromosomes fuse to form a single centromere or two. The resulting balanced karyotype has only 45 chromosomes including the translocated one, which is the result of a fusion of the long arms of two acrocentric chromosomes (5).

What is the karyotype for Down syndrome?

The trisomy 21 karyotype figure shows the chromosomal arrangement, with the prominent extra chromosome 21. Trisomy 21 is the cause of approximately 95% of observed Down syndrome, with 88% coming from nondisjunction in the maternal gamete and 8% coming from nondisjunction in the paternal gamete.

Why does Robertsonian translocation cause Down syndrome?

Down syndrome and more Patau syndrome is a result of an extra copy of chromosome 13 in a developing fetus’s DNA. If your Robertsonian translocation fuses chromosome 13 with another chromosome, you may be a carrier for Patau syndrome. Most cases of this trisomy aren’t inherited, but it’s possible.

Can translocation cause Down syndrome?

Yes. Translocation Down Syndrome is the only type of Down Syndrome that can be passed down from a parent who does not have features of Down Syndrome. If a parent has balanced translocation, there is an up to 15% chance of having another child with Down Syndrome.

What are the symptoms of Robertsonian translocation?

Robertsonian translocation is the most common form of chromosomal translocation in humans….Other symptoms include:

• intellectual disability.
• heart defects.
• brain or spinal cord abnormalities.
• small or poorly developed eyes.
• weak muscles.

Can people with Robertsonian translocation have children?

Many people with Robertsonian translocation have healthy children. The condition can, however, impact on their chances of having a family. Women with the translocation may find it difficult to get pregnant. They also have a higher chance of having a miscarriage than those without Robertsonian translocation.

What diseases does translocation cause?

Examples

What happens if a karyotype test is abnormal?

Abnormal karyotype test results could mean that you or your baby have unusual chromosomes. This may indicate genetic diseases and disorders such as: Down syndrome (also known as trisomy 21), which causes developmental delays and intellectual disabilities.

What would the karyotype look like if the person has Down syndrome?

The number 46 indicates that there were 46 chromosomes present, and the XX indicates there were two X chromosomes so the person is female. If the individual was a boy, it would say 46, XY. If your child has been diagnosed with Down syndrome, the karyotype image would have an extra copy of chromosome 21 as seen below.

Is there a cure for Robertsonian translocation?

In most cases, Robertsonian translocation does not cause any health problems or require treatment. People who carry the abnormality, however, may pass it on to their children. Aspiring parents may wish to seek genetic counseling before starting a family.

Can a person with Robertsonian translocation have Down syndrome?

Trisomy 21 is also known as Down syndrome. Down syndrome is the world’s most common genetic disorder. If your Robertsonian translocation fuses another chromosome with chromosome 21, you may be genetically more predisposed to have a baby with Down syndrome.

Which is the normal karyotype for Down syndrome?

The karyotype revealed 46,XX,rob (14;21) (q10;q10),+21. The carrier status for balanced translocations for both parents were identified by peripheral blood karyotype and was found to be have normal karyotype. Conclusions: Translocation in Down syndrome is usually of Robertsonian type with fusion of chromosome 21 to D or G group chromosome.

How is chromosome 21 attached in Translocation Down syndrome?

In translocation Down syndrome, an extra copy of chromosome 21 is attached to a different chromosome. For example, when an extra chromosome 21 is attached to chromosome 14, it looks like the picture below.

How many chromosomes are lost in a Robertsonian translocation?

A Robertsonian event usually results in a genetic complement of 45 chromosomes due to the fusion of two long (q) chromosome arms and the loss of the corresponding two short arms. In a retrospective review of 333 infertile men, 10 (3%) had Robertsonian translocations ( Antonelli et al., 2000).