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Disease Profile

Chromosome 9 inversion

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Inversion 9


Chromosome Disorders


Chromosomes are the structures found in every cell of the body that contain our DNA, the instructions that tell our body what to do. Humans have 23 pairs of chromosomes, which means that each human cell contains 46 chromosomes. Each chromosome has a p and q arm; p is the short arm and q is the long arm. The p arm is always on the top and the q arm is on the bottom.[1]

An inversion occurs when there are two breaks in one chromosome. The segment between the breakpoints flips around and reinserts back into the chromosome. Genetic material may of may not be lost as a result of the chromosome breaks. If both breaks occur in the same arm of the chromosome, this is called a paracentric inversion. If one break occurs in the short arm and the other in the long arm of the chromosome, then this is called a pericentric inversion.[2] 

Chromosome 9 inversion 
is one of the most common structural balanced chromosomal variants, with an estimated incidence of about 3.5 percent.[3] It remains unclear, however, if these rearrangements have clinical significance.[3][4] In some cases, it has been associated with congenital anomalies, growth retardation, infertility, recurrent pregnancy loss, and cancer.[3][4][5]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


  1. Chromosome Abnormalities. National Human Genome Research Institute Web site. January 6, 2016; https://www.genome.gov/11508982#6.
  2. Can changes in the structure of chromosomes affect health and development?. Genetics Home Reference (GHR). https://ghr.nlm.nih.gov/primer/mutationsanddisorders/structuralchanges. Accessed 5/24/2017.
  3. Jeong S-Y, Kim B-Y, Yu JE. De Novo Pericentric Inversion of Chromosome 9 in Congenital Anomaly. Yonsei Med J. 2010; 51(5):775-780. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908878/.
  4. Muthuvel A, Ravindran M, Chander A, Subbian C. Pericentric inversion of chromosome 9 causing infertility and subsequent successful in vitro fertilization. Nigerian Medical Journal?: Journal of the Nigeria Medical Association. 2016; 57(2):142-144. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4872494/.
  5. Dana M, Stoian V. Association of Pericentric Inversion of Chromosome 9 and Infertility in Romanian Population. Maedica (Buchar). 2012; 7(1):25-29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484792/.