Overview
Down syndrome is a genetic disorder caused by an extra full or partial copy of chromosome 21. This extra genetic material leads to developmental changes and physical features, causing lifelong intellectual disability and developmental delays. It is the most common genetic chromosomal disorder and cause of learning disabilities in children. Down syndrome varies in severity among individuals, and it commonly causes other medical abnormalities, including heart and gastrointestinal disorders.
Understanding the disease
Symptoms
The symptoms of Down syndrome can vary depending on the individual. Some common physical features include a flattened face, small head, short neck, protruding tongue, upward slanting eyelids, unusually shaped or small ears, poor muscle tone, broad short hands with a single crease in the palm, relatively short fingers and small hands and feet, and excessive flexibility. Additionally, around half of children with Down syndrome are born with some type of congenital heart defect, and they may also be at risk for gastrointestinal defects, immune disorders, sleep apnea, and other health issues. Intellectual disability is also common in individuals with Down syndrome, with language delays and memory problems being typical. It's important to consult a doctor if you have any concerns about your child's growth and development.
Risk Factors
Risk factors for having a child with Down syndrome include:
- Advancing maternal age: A woman's chances increase with age due to the higher risk of chromosomal abnormalities in older eggs.
- Being a carrier of the genetic translocation for Down syndrome: Both men and women can pass the genetic translocation on to their children. Please note that these risk factors do not guarantee that a child will have Down syndrome, but they can increase the likelihood.
Development
Down syndrome is a genetic disorder caused by abnormal cell division, resulting in an extra full or partial copy of chromosome 21. There are three genetic variations that can cause Down syndrome:
- Trisomy 21: This is the most common cause, accounting for about 95% of cases. In trisomy 21, the person has three copies of chromosome 21 in all cells, instead of the usual two copies. This extra genetic material is responsible for the characteristic features and developmental problems of Down syndrome. It is caused by abnormal cell division during the development of the sperm cell or the egg cell.
- Mosaic Down syndrome: This rare form of Down syndrome occurs when a person has only some cells with an extra copy of chromosome 21. The mosaic of normal and abnormal cells is caused by abnormal cell division after fertilization. Both trisomy 21 and mosaic Down syndrome result from abnormalities in chromosome 21, but the difference lies in the distribution of extra genetic material within the body's cells. In trisomy 21, all cells have the extra copy of chromosome 21, while in mosaic Down syndrome, only some cells have this extra material.
Assessment and Diagnosis
Triage
You should see a doctor if Down syndrome is suspected, especially if you have concerns about your pregnancy or your child's growth and development. Doctors can perform diagnostic tests to confirm the presence of Down syndrome before or after birth. Early diagnosis allows for early intervention and support, which can improve the quality of life for children and adults with the disorder.
Diagnosis
Diagnosis of Down syndrome can be done through various tests, depending on the stage of pregnancy or the age of the individual. During pregnancy: Screening tests, such as the first trimester combined test and the integrated screening test, can help identify the likelihood or chances of having a baby with Down syndrome. However, these tests can't provide a definitive diagnosis. Further diagnostic tests, like chorionic villus sampling (CVS) or amniocentesis, are necessary for a conclusive diagnosis. These tests involve analyzing fetal chromosomes from cells taken from the placenta or amniotic fluid, respectively. For newborns: After birth, a baby's initial diagnosis might be based on their appearance, but further confirmation is necessary through a chromosomal karyotype test. This test analyzes the baby's chromosomes using a sample of their blood to check for an extra chromosome 21, which is characteristic of Down syndrome. It's essential to consult with a healthcare provider to discuss the types of tests, their advantages and disadvantages, benefits, risks, and the interpretation of results. Genetics counseling may also be recommended to help guide the decision-making process.
Management and Treatment
Complications
Potential complications of Down syndrome include:
- Congenital heart defects
- Gastrointestinal (GI) defects
- Immune disorders
- Sleep apnea
- Obesity
- Spinal problems
- Leukemia (in young children)
- Dementia (beginning around age 50)
- Endocrine problems
- Dental problems
- Seizures
- Ear infections
- Hearing and vision problems Early medical intervention and regular check-ups can help manage these complications and improve the quality of life for individuals with Down syndrome.
Preparing for medical consultation
Preparing for an appointment concerning Down syndrome involves several steps:
- Gather information: Before the appointment, research Down syndrome and its characteristics, as well as the resources available in your area for individuals with the condition.
- Write down symptoms and concerns: Take note of any symptoms or concerns you have regarding your child's development, health, or well-being.
- Prepare a family history: Compile information about your child's family history, including details from both the maternal and paternal sides of the family.
- Bring medical records: Bring any baby books, developmental records, or other relevant medical documents to the appointment.
- Ask for early intervention programs: Inquire about early intervention programs in your area that can provide support and stimulation to help develop motor, language, social, and self-help skills.
- Explore educational options: Discuss educational options with your healthcare provider and the school, such as regular classes, special education classes, or a combination of both, based on your child's needs.
- Take support: Consider bringing a family member or friend to the appointment for emotional support. Remember that the appointment may bring up a range of emotions. It's essential to seek information and support to best care for and advocate for your child with Down syndrome.