How does robertsonian translocation occur

This extra chromosome results in small stature and low muscle tone, among other…. Genes contain instructions for life and survival. New genetic discoveries offer insights into how life works, and hope for preventing and curing…. What to know about Robertsonian translocation. Medically reviewed by Carissa Stephens, R. What is it? Symptoms Causes Treatment Fertility Outlook Robertsonian translocation is the most common form of chromosomal translocation in humans.

What is Robertsonian translocation? Share on Pinterest Robertsonian translocation does not always cause symptoms. How does it affect fertility? Exposure to air pollutants may amplify risk for depression in healthy individuals. Costs associated with obesity may account for 3. Related Coverage. What is DNA and how does it work? Medically reviewed by Alana Biggers, M. Cleft lip and cleft palate Some infants are born with a cleft lip, cleft palate, or both, often leading to speech, hearing, and feeding problems.

What to know about Down syndrome. Medically reviewed by University of Illinois. And when people with this translocation carry a child to term, the child may be at a higher risk for chromosomal imbalance. If either you or your partner has this translocation, a risk assessment that analyzes the DNA you carry as well as genetic counseling may need to be considered for future pregnancies.

A monosomy is a genetic alteration in which one half of a chromosome pair is missing. Robertsonian translocations can result in pregnancies that carry monosomy 14 and monosomy Both are considered nonviable. A trisomy is a genetic alteration in which there is an extra copy of a chromosome in a DNA strand, throwing the chain off balance. A Robertsonian translocation can result in trisomy 14 or trisomy Trisomy 21 is also known as Down syndrome. If your Robertsonian translocation fuses another chromosome with chromosome 21, you may be genetically more predisposed to have a baby with Down syndrome.

Patau syndrome is a rare genetic condition that can cause heart defects and brain and spinal cord abnormalities. If your Robertsonian translocation fuses chromosome 13 with another chromosome, you may be a carrier for Patau syndrome. Babies born with Patau syndrome rarely live more than one year. Other monosomies and trisomies that can occur with Robertsonian translocations are nonviable.

This is why having a Robertsonian translocation goes along with a higher risk of miscarriage. Typically, people born with a Robertsonian translocation are healthy and have average life expectancies. But finding out you have this genetic abnormality, and the possibility of it affecting your pregnancy or your children, can be confusing and stressful.

Viability outcomes for certain genetic conditions vary considerably. The remaining possibilities are a child with normal chromosomes, a child with the balanced translocation, and a child with Down syndrome due to the unbalanced form of the translocation causing trisomy This child has inherited the Robertsonian translocation chromosome as well as a normal chromosome 21 from the carrier parent, and a normal 14 and a normal 21 chromosome from the other parent.

A parent who is a carrier for a Robertsonian translocation involving chromosome 21 therefore has a high risk of having a child affected with Down syndrome, compared with the low recurrence in regular trisomy 21 Down syndrome which is due to an error in cell division, and has a recurrence risk of about 1 in This article has been cited by other articles in PMC.

S2 Fig: A der 13;14 , and a a single copy of chromosomes 14, and two copies of chromosomes 13, 15, 21 and 22, b a single copy of chromosomes 13 and 14, two copies of chromosomes 15 and 22, and three copies of chromosome 21, c a single copy of chromosomes X and 14, and two copies of chromosomes 15, 21 and 22, d a single copy of chromosomes Y, 13 and 14, and two copies of chromosomes X, 15, 21 and S3 Fig: A der 13;15 , a single copy of chromosomes 13 and 14, and two copies of chromosomes 14, 21 and S4 Fig: A der 13;21 , and a a single copy of chromosomes 13 and 21, and two copies of chromosomes 14, 15 and 22, b a single copy of chromosome 13, and two copies of chromosomes 14, 15, 21 and S5 Fig: A der 13;22 , a single copy of chromosomes 13 and 22, and two copies of chromosomes 14, 15 and S6 Fig: A der 14;14 and two copies of chromosomes 13, 15, 21 and S7 Fig: A der 14;15 , a single copy of chromosomes 14 and 15, and two copies of chromosomes 13, 21 and S8 Fig: A der 14;21 , and a a single copy of chromosome 14, and two copies of chromosomes 13, 15, 21 and 22, b a der 14;22 , a single copy of chromosomes 21 and 22, and two copies of chromosomes 13 and S9 Fig: A der 14;22 , a single copy of chromosomes 14 and 22, and two copies of chromosomes 13, 15 and S10 Fig: A der 15;15 and two copies of chromosomes 13, 14, 21 and S11 Fig: A der 15;21 , and a a single copy of chromosomes 15 and 21, and two copies of chromosomes 13, 14 and 22, b a single copy of chromosomes 15, and two copies of chromosomes 13, 14, 21 and S12 Fig: A der 15;22 , a single copy of chromosomes 15 and 22, and two copies of chromosomes 13, 14 and S13 Fig: A der 21;21 , a single copy of chromosome 21, and two copies of chromosomes 13, 14, 15 and S14 Fig: A der 21;22 , apparently balanced translocations between chromosomes 3 and 14 [t 3;14 q27;q13 ], a single copy of chromosomes 3, 14, 21 and 22, and two copies of chromosomes 13 and S15 Fig: A der 22;22 and two copies of chromosomes 13, 14, 15 and Introduction Robertsonian translocations ROBs are chromosomal rearrangements that result from the fusion of the entire long arms of two acrocentric chromosomes.

Materials and Methods From Jan. Results Of the , specimens karyotyped in this study, were identified to have ROBs. Balanced Robertsonian translocations ROBs detected in adults.

Balanced Robertsonian translocations ROBs detected in children. Open in a separate window. Notes: T: total; M: male; F: female;. Nonrandom distributions of different subtypes of unbalanced ROBs of the individuals with unbalanced ROBs are children with ages ranging from newborn to 12 years-old Table 2. Mosaic ROBs The 9 mosaic ROBs in Table 3 are composed of 3 balanced Cases 23, 24, and 25 , 4 unbalanced der 21;21 Cases 20, 21, and 22 , and 2 unbalanced being both mosaic and complex case 4 identified in a newborn boy with DS and case 17 identified in a 27 years-old female with atypical features of Turner syndrome.

Discussion Balanced ROB carriers It is well known that balanced ROB carriers usually have normal phenotype, but can have problem of infertility associated with oligospermia in male adults, miscarriage or infertility in female adults. Complex ROBs In the current study, we reported 18 cases with multiple chromosomal abnormalities with at least one of them involving an acrocentric chromosome.

Weaknesses of this study There are several weaknesses present in this study: 1 bias of ascertainments; 2 incomplete clinical information about these individual carrying ROBs; and 3 incomplete follow-up molecular testing, especially for these ROBs with homologous ROBs. Supporting Information S1 Fig A der 13;13 and two copies of chromosomes 14, 15, 21 and TIF Click here for additional data file. S2 Fig A der 13;14 , and a a single copy of chromosomes 14, and two copies of chromosomes 13, 15, 21 and 22, b a single copy of chromosomes 13 and 14, two copies of chromosomes 15 and 22, and three copies of chromosome 21, c a single copy of chromosomes X and 14, and two copies of chromosomes 15, 21 and 22, d a single copy of chromosomes Y, 13 and 14, and two copies of chromosomes X, 15, 21 and S3 Fig A der 13;15 , a single copy of chromosomes 13 and 14, and two copies of chromosomes 14, 21 and S4 Fig A der 13;21 , and a a single copy of chromosomes 13 and 21, and two copies of chromosomes 14, 15 and 22, b a single copy of chromosome 13, and two copies of chromosomes 14, 15, 21 and S5 Fig A der 13;22 , a single copy of chromosomes 13 and 22, and two copies of chromosomes 14, 15 and S6 Fig A der 14;14 and two copies of chromosomes 13, 15, 21 and S7 Fig A der 14;15 , a single copy of chromosomes 14 and 15, and two copies of chromosomes 13, 21 and S8 Fig A der 14;21 , and a a single copy of chromosome 14, and two copies of chromosomes 13, 15, 21 and 22, b a der 14;22 , a single copy of chromosomes 21 and 22, and two copies of chromosomes 13 and S9 Fig A der 14;22 , a single copy of chromosomes 14 and 22, and two copies of chromosomes 13, 15 and S10 Fig A der 15;15 and two copies of chromosomes 13, 14, 21 and S11 Fig A der 15;21 , and a a single copy of chromosomes 15 and 21, and two copies of chromosomes 13, 14 and 22, b a single copy of chromosomes 15, and two copies of chromosomes 13, 14, 21 and S12 Fig A der 15;22 , a single copy of chromosomes 15 and 22, and two copies of chromosomes 13, 14 and S13 Fig A der 21;21 , a single copy of chromosome 21, and two copies of chromosomes 13, 14, 15 and S14 Fig A der 21;22 , apparently balanced translocations between chromosomes 3 and 14 [t 3;14 q27;q13 ], a single copy of chromosomes 3, 14, 21 and 22, and two copies of chromosomes 13 and S15 Fig A der 22;22 and two copies of chromosomes 13, 14, 15 and Data Availability All relevant data are within the paper.

References 1. A cytogenetic survey of 14, newborn infants. Incidence of chromosome abnormalities. Clin Genet. Chromosome Abnormalities and genetic Counseling.

Robertsonian translocations: mechanisms of formation, aneuploidy, and uniparental disomy and diagnostic considerations. Genet Test. Nielsen J, Wohlert M.