What are the other Names for this Condition? (Also known as/Synonyms)

• Chromosome 1 Disorders

What are Disorders of Chromosome 1? (Definition/Background Information)

There are many disorders that are caused by abnormalities on chromosomes 1. Some are more common than others. Researchers know more about certain chromosomal disorders than others. Information is constantly being added through research, better documentation, and increased awareness.

Chromosomes are microscopic protein structures present in each cell nucleus that carry genetic information in the form of DNA (deoxyribonucleic acid). Humans have 46 chromosomes in the cell nucleus, in 23 pairs, of which one pair is named the sex chromosome. In males, it is designated XY, for chromosome X and chromosome Y; while, in females, it is designated XX, for a pair of chromosome X. The other 22 pairs of chromosomes are numbered chromosome 1 through 22.

During conception, the embryo inherits one copy of each chromosome from each parent (i.e., mother and father). Any alteration in the chromosome numbers or structure can result in mild to severe genetic abnormalities. Specialized genetic testing techniques are often required to confirm the diagnosis.

Chromosome 1 Disorders are disorders involving chromosome 1. Some of the disorders include:

Chromosome 1p Deletion Syndrome: Chromosome 1p Deletion Syndrome is a genetic disorder characterized by the deletion of genetic material on the short arm of chromosome 1. It can result in a range of developmental delays, intellectual disability, characteristic facial features, low muscle tone, seizures, and heart defects. Treatment focuses on managing symptoms and providing supportive care tailored to the individual's specific needs.

Chromosome 1p Duplication Syndrome: Chromosome 1p Duplication Syndrome involves the presence of extra genetic material on the short arm of chromosome 1. This condition can lead to developmental delays, intellectual disability, speech and language delays, behavioral issues, and various physical abnormalities. Treatment typically involves early intervention and supportive care to address developmental and medical needs.

Chromosome 1p36 Deletion Syndrome: Chromosome 1p36 Deletion Syndrome is a genetic disorder caused by the deletion of genetic material on the short arm of chromosome 1. It is characterized by developmental delays, intellectual disability, low muscle tone, distinct facial features, seizures, heart defects, and other medical issues. Treatment involves early intervention programs, therapies to address developmental delays, medical management of symptoms, and ongoing support.

Chromosome 1q Duplication Syndrome: Chromosome 1q Duplication Syndrome involves the presence of extra genetic material on the long arm of chromosome 1. It can lead to developmental delays, intellectual disability, speech and language delays, behavioral issues, physical abnormalities, and various health problems. Treatment focuses on managing symptoms, addressing developmental needs, and providing supportive care.

Chromosome 1q21.1 Microdeletion Syndrome: Chromosome 1q21.1 Microdeletion Syndrome is a genetic disorder characterized by the deletion of a small segment of genetic material on the long arm of chromosome 1. It can cause developmental delays, intellectual disability, autism spectrum disorder, distinctive facial features, heart defects, and other medical conditions. Treatment involves early intervention, supportive care, and management of associated medical issues.

Chromosome 1q21.1 Duplication Syndrome: Chromosome 1q21.1 Duplication Syndrome involves the presence of extra genetic material on the long arm of chromosome 1. It can result in developmental delays, intellectual disability, behavioral challenges, autism spectrum disorder, physical abnormalities, and other health issues. Treatment focuses on addressing developmental needs, providing supportive care, and managing associated medical conditions.

Chromosome 1q23.3 Microdeletion Syndrome: Chromosome 1q23.3 Microdeletion Syndrome is a rare genetic disorder characterized by the deletion of a small segment of genetic material on the long arm of chromosome 1. It can result in developmental delays, intellectual disability, speech and language difficulties, growth abnormalities, distinctive facial features, and other medical issues. Treatment focuses on managing symptoms and providing supportive care tailored to the individual's needs.

Chromosome 1q42 (and beyond) Deletions: Chromosome 1q42 (and beyond) Deletions involve the deletion of genetic material on the long arm of chromosome 1, specifically at the 1q42 region and beyond. These deletions can cause a variety of symptoms and developmental challenges, which can vary widely depending on the specific location and size of the deletion. Treatment typically involves addressing the specific symptoms and providing supportive care.

GATAD2B Syndrome: GATAD2B Syndrome is a rare genetic disorder caused by mutations in the GATAD2B gene. It is characterized by intellectual disability, developmental delays, speech and language difficulties, behavioral challenges, and distinctive facial features. Treatment involves early intervention programs, therapies to address developmental delays, and supportive care to manage associated symptoms and improve quality of life.

Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus Syndrome: Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus Syndrome is a rare genetic disorder characterized by overgrowth of the brain (megalencephaly), abnormal folding of the brain (polymicrogyria), extra fingers or toes (polydactyly), and excessive accumulation of cerebrospinal fluid in the brain (hydrocephalus). Treatment focuses on managing symptoms and may involve neurosurgical interventions to address hydrocephalus and supportive care for developmental and medical needs.

Supernumerary Ring Chromosome 1 Syndrome: Supernumerary Ring Chromosome 1 Syndrome is a chromosomal disorder caused by the presence of an extra ring-shaped chromosome derived from chromosome 1. It can lead to developmental delays, intellectual disability, growth abnormalities, characteristic facial features, and other medical issues. Treatment involves early intervention programs, therapies to address developmental delays, and supportive care tailored to the individual's needs.

IRF6-Related Disorders: IRF6-Related Disorders are a group of genetic conditions caused by mutations in the IRF6 gene. They can result in a spectrum of abnormalities affecting the development of the face, palate, and teeth. Examples include Van der Woude Syndrome, characterized by cleft lip and/or palate and lip pits, and Popliteal Pterygium Syndrome, which involves facial abnormalities, limb defects, and webbing of the skin around the joints. Treatment typically involves surgical interventions to correct the specific abnormalities and multidisciplinary care to manage associated symptoms and support affected individuals and their families.

Van der Woude Syndrome: Van der Woude Syndrome is a genetic disorder characterized by the presence of cleft lip and/or cleft palate, and in some cases, small depressions or pits in the lower lip known as lip pits. It is caused by mutations in the IRF6 gene. The cleft lip and/or palate are present at birth and may require surgical intervention to repair the separation of the lip and/or palate. Speech therapy may also be recommended to address speech difficulties that can arise due to the cleft. Lip pits, although harmless, may be present and do not typically require treatment. Early diagnosis and appropriate management can help individuals with Van der Woude Syndrome lead healthy lives and achieve optimal outcomes.

This article is a resource with links to other more specific disorders. Information on each Chromosome 1 Disorder may be viewed by clicking on the respective subtypes (above).

Information to join DoveMed’s patient forum called MyCIrcles to learn and manage the condition is also included. We are adding more information to this page periodically. Please bookmark this page for future reference and visit for updated content.

You can join Chromosome Disorders MyCircles patient forum by visiting here: https://www.dovemed.com/mycircles/circles/all