Summary about Disease
Chromosome 17q21.31 microdeletion syndrome is a rare genetic disorder caused by a small missing piece (microdeletion) on chromosome 17 at a specific location labeled q21.31. This deletion affects multiple genes in that region, leading to a variety of physical and developmental problems. It's often characterized by intellectual disability, developmental delays, distinct facial features, and behavioral issues. The severity of the condition can vary significantly among affected individuals.
Symptoms
The symptoms of Chromosome 17q21.31 microdeletion syndrome can vary but commonly include:
Intellectual disability (mild to moderate)
Developmental delays (speech, motor skills)
Hypotonia (low muscle tone)
Distinct facial features: long face, prominent forehead, high arched eyebrows, wide mouth with full lips, pointed chin, and ear abnormalities.
Behavioral problems: hyperactivity, anxiety, autistic traits, and sleep disturbances.
Seizures (in some cases)
Skeletal abnormalities: scoliosis, hip dysplasia, or clubfoot.
Heart defects (in some cases)
Causes
The cause is a microdeletion on chromosome 17 at the q21.31 band. This deletion typically occurs de novo (new mutation), meaning it's not inherited from the parents. Rarely, it can be inherited from a parent who carries a balanced translocation involving the 17q21.31 region, but who does not show symptoms. The size of the deletion can vary, which impacts the severity of the syndrome. The *KANSL1* gene, located within this region, is considered a key gene responsible for many of the syndrome's features.
Medicine Used
4. Medicine used There is no specific medicine to "cure" Chromosome 17q21.31 microdeletion syndrome. Treatment focuses on managing specific symptoms and providing supportive care. This may include:
Anticonvulsant medications for seizures
Medications to manage behavioral problems (e.g., ADHD medications, anti-anxiety medications)
Physical therapy to improve motor skills and muscle tone
Speech therapy to improve communication skills
Occupational therapy to improve daily living skills
Heart medication and/or surgery if heart defects are present.
Is Communicable
No, Chromosome 17q21.31 microdeletion syndrome is not communicable. It is a genetic disorder, not an infectious disease.
Precautions
Since it is not communicable, there are no precautions to prevent its spread. Genetic counseling and prenatal testing (if a parent has a known translocation) are options for families with a history of this syndrome who are planning to have children. The best precaution is genetic testing if there is a family history.
How long does an outbreak last?
This condition is not an outbreak. Outbreaks are associated with infectious diseases. Chromosome 17q21.31 microdeletion syndrome is a lifelong genetic condition.
How is it diagnosed?
Diagnosis typically involves:
Clinical evaluation: Based on the presence of characteristic physical features, developmental delays, and other symptoms.
Chromosomal microarray analysis (CMA): This is the most common test used to detect the microdeletion on chromosome 17q21.31.
Fluorescence In Situ Hybridization (FISH): Can be used to confirm the diagnosis.
Karyotype analysis: To assess chromosomes and may identify large translocations.
Genetic testing: To help identify the specific deletion region.
Timeline of Symptoms
9. Timeline of symptoms The timeline of symptom onset can vary, but generally:
Prenatal: Some abnormalities (e.g., heart defects) may be detected during prenatal ultrasound.
Infancy: Hypotonia, feeding difficulties, and developmental delays may become apparent. Distinct facial features are usually noticeable in infancy.
Early Childhood: Speech delays and motor skill delays become more prominent. Behavioral problems may emerge.
Later Childhood/Adolescence: Intellectual disability is more clearly defined. Scoliosis or other skeletal abnormalities may develop.
Important Considerations
Early diagnosis and intervention are crucial to optimize development and quality of life.
Affected individuals benefit from a multidisciplinary approach involving pediatricians, geneticists, developmental specialists, therapists, and other healthcare professionals.
Parents and caregivers need support and resources to cope with the challenges of raising a child with Chromosome 17q21.31 microdeletion syndrome.
Genetic counseling is important for families to understand the inheritance pattern and recurrence risk.
The severity of the syndrome can vary considerably among individuals.