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Disease Profile

1q duplications

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)

Partial trisomy 1q; Partial trisomy of the long arm of chromosome 1; Partial trisomy of chromosome 1q;


Chromosome Disorders


Chromosome 1q duplications are chromosome abnormalies that occurs when there is an extra copy of genetic material on the long arm (q) of chromosome 1. The severity of the condition and the signs and symptoms depend on the size and location of the duplication and which genes are involved. Features that may occur in people with chromosome 1q duplications include developmental delay and learning disabilities, slow growth and/or short stature, various birth defects (such as cleft palate or heart defect) and specific facial features (such as a small, receding jaw).[1] Most cases are not inherited from a parent, but a person with the duplication can pass it on to his/her children. Treatment is based on the signs and symptoms present in each person.


Symptoms of chromosome 1q duplications generally depend on the size and location of the duplication, and the genes involved. Therefore, symptoms vary. For example, people who have small duplications near the tip of the long (q) arm of chromosome 1 are often mildly affected, while those with larger duplications often have more severe learning difficulties. Children with large duplications that extend to near the center of the chromosome tend to have more severe birth defects and a shortened life expectancy.[1]

Some of the more common features that may occur in people with a chromosome 1q duplications include:

  • small and/or receding lower jaw
  • high and narrow roof of mouth (palate), and/or cleft palate
  • learning difficulties and developmental delay
  • heart defects
  • slow growth and short stature

Below is a summary of some additional features that have been reported in people with certain types of chromosome 1q duplications, according to a guide provided by Unique. Unique draws information from both the published medical literature and from a survey of members with a chromosome 1q duplication.

Duplications including material near the middle of the chromosome (centromere):

  • typically severely affected, sometimes unable to survive infancy independently
  • some joints fixed in a rigid, bent position
  • hydrocephalus (an excess of fluid around the brain)
  • no development of speech
  • feeding difficulties

Duplications between bands 1q23-q25 and 1q41:

  • small mouth that may not open fully
  • low-set, backwards-rotated ears

Large duplications between bands 1q31 and the end of the long arm:

  • kidney defects and anomalies of the urinary tract
  • minor anomalies of the urinary and genital systems in boys
  • eye or vision abnormalities (e.g. strabismus, small eyes, or blindness)
  • blockage or narrowing of part of the gastrointestinal tract
  • extra fingers or toes, and/or crowded, overriding toes
  • low, backwards-rotated ears
  • increased risk of respiratory infections

Small duplications from band 1q4:

  • large head with a prominent forehead
  • initial feeding difficulties and failure to thrive
  • highly variable degree of learning difficulty (sometimes no learning difficulty)[1]

To read more about these signs and symptoms and additional symptoms reported in people with chromosome 1q duplication, read Unique's guide entitled 'Duplications of 1q.'


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

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • Genetics Home Reference (GHR) contains information on 1q duplications. This website is maintained by the National Library of Medicine.
    • Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about 1q duplications.

      In-Depth Information

      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss 1q duplications. Click on the link to view a sample search on this topic.

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