Down syndrome and other syndromes

Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small “packages” of genes in the body. They determine how a baby’s body forms and functions as it grows during pregnancy and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby’s body and brain develop, which can cause both mental and physical challenges for the baby. Even though people with Down syndrome might act and look similar, each person has different abilities. People with Down syndrome usually have an IQ (a measure of intelligence) in the mildly-to-moderately low range and are slower to speak than other children. Some common physical features of Down syndrome include:

• A flattened face, especially the bridge of the nose
• Almond-shaped eyes that slant up
• A short neck
• Small ears
• A tongue that tends to stick out of the mouth
• Tiny white spots on the iris (colored part) of the eye
• Small hands and feet
• A single line across the palm of the hand (palmar crease)
• Small pinky fingers that sometimes curve toward the thumb
• Poor muscle tone or loose joints
• Shorter in height as children and adults

Health Problems

Many people with Down syndrome have the common facial features and no other major birth defects. However, some people with Down syndrome might have one or more major birth defects or other medical problems. Some of the more common health problems among children with Down syndrome are listed below.8

• Hearing loss
• Obstructive sleep apnea, which is a condition where the person’s breathing temporarily
• stops while asleep
• Ear infections
• Eye diseases
• Heart defects present at birth
• Health care providers routinely monitor children with Down syndrome for these conditions.