Down Syndrome, the most common and well-known chromosomal disorder, is the most common cause of intellectual disability.

The three copies, or trisomy, of chromosome 21 in these patients gives rise to multiple systemic complications, of which there is a wide variation.

The true incidence of this condition is not known and is likely to be higher than the estimated one in 600-700 live births in Malaysia, as about one quarter to half of foetuses with Down Syndrome are spontaneously aborted in the first and second trimesters of pregnancy.

Health problems

Children with Down Syndrome have multiple health problems.

Aside from cognitive impairment – the degree of which is variable and may be mild, moderate or occasionally severe – they have significant risk of developing:

• Hearing loss
• Obstructive sleep apnoea
• Eye disease
• Congenital heart defects
• Neurologic dysfunction
• Gastrointestinal atresia
• Hip dislocation
• Thyroid disease
• Transient myeloproliferative disorder, which can lead to leukaemia (less common), and
• Hirschsprung disease.

There were many childhood deaths from Down Syndrome previously, but with improvements in medical care, there is increased life expectancy for these children, with many reaching adulthood and even becoming senior citizens.

In addition, their quality of life has been enhanced.

However, there are no medical treatments for the intellectual disability associated with Down Syndrome.

Medical care

There are many aspects to the medical care for Down Syndrome patients.

Genetic counselling is necessary for parents to facilitate understanding and acceptance of the condition, as well as providing regular, up-to-date and balanced information delivered in a supportive and respectful manner about the condition, and its risk of recurrence in future children.

The standard immunisations have to be administered together with other aspects of routine child care.

The specific manifestations of Down Syndrome and its associated conditions, i.e. endocrine (hormones), infectious, cardiac (heart), respiratory (lungs), neurologic (nerves), psychiatric (mental), dermatologic (skin) and dental disorders, have to be managed.

The measures recommended by the American Academy of Paediatrics for children with Down Syndrome include:

• Frequent ear examinations and hearing evaluations (annually after early infancy) because of the increased risk for otitis media (middle ear infection) and secondary hearing loss.
• Monitoring for obstructive sleep apnoea – all children should be referred for a sleep study by the age of four years.
• Thyroid function testing in the newborn, at six and 12 months of life, and annually thereafter, because of the high risk for acquired hypothyroidism (low thyroid hormones).
• Monitoring for gastroesophageal reflux and swallowing difficulties, as well as for the development of coeliac disease.
• Monitoring for the development of leukaemia in the first few years of life.
• Infants who have congenital heart disease should be monitored for the development of heart failure and pulmonary hypertension in early infancy, while adolescents and adults should be monitored for the development of acquired heart valve disease.
• Annual eye examinations because of the increased risk for refractive errors (shortsightedness and longsightedness).
• Monitoring for the development of atlantoaxial instability (excessive movement of the junction between the atlas [C1] and axis [C2] bones in the neck, as well as evaluation for signs and symptoms of myelopathy (injury to the spinal cord) every clinic visit.
• Monitoring of cognitive function and evaluation for behavioural problems, autism and the development of seizures.

Parents should also be counselled that individuals with Down syndrome are at increased risk for sexual abuse and that the likely perpetrators are people well-known to the child.

Surgical care

Appropriate surgical care of Down Syndrome-associated conditions should be provided.

Such surgical care includes:

• Timely surgery for cardiac anomalies, which is crucial for optimal survival.
• Prompt surgical repair for gastrointestinal anomalies – most commonly, duodenal atresia and Hirschsprung disease.
• Surgery to stabilise the upper segment of the cervical spine if it causes significant nerve problems.
• Extraction of congenital cataracts soon after birth, and subsequent correction with glasses or contact lenses.
• Careful anaesthetic airway management during any surgery, because of the associated risk of cervical spine instability.
• Adenotonsillectomy (surgery to remove both the adenoids and the tonsils) to manage obstructive sleep apnoea, if needed.

Early intervention

The first years of life are critical in every child’s development, as this is when all children go through the most rapid and developmentally significant changes.

During these early years, the basic physical, cognitive, language, social and self-help skills lay the foundation for future progress according to predictable developmental patterns.

Children with Down Syndrome typically face delays in certain developmental milestones, so early intervention is highly recommended.

It can begin any time after birth, but the sooner it starts, the better.

Early intervention programmes involve therapy, exercises and activities designed to address developmental delays that may be experienced by children with Down Syndrome or other disabilities.

Early interventions that address developmental delays may also improve the child’s social quotient, which is the measure of the ability to build and maintain a network of friends over a long period of time.

Speech and language therapy are of help to children with Down Syndrome, who usually learn to talk later than other children.

They typically understand speech better than they are able to speak.

Physical therapy helps to ensure that daily tasks and activities are easier.

Techniques are taught to parents to help the child learn to sit, stand and walk safely.

Occupational therapy helps to improve functional skills in motor areas like eating and handling objects, and fine motor skills like buttoning and unbuttoning clothes.

Nutritional counselling helps a child with Down Syndrome, who typically tends to be overweight.

This is because they burn calories more slowly than other children, and/or there is limited participation in regular physical activities.

Vocational training helps train teenagers and young adults for jobs that match their strongest skills.

This helps them be independent and reach their fullest potential.

Support groups

Support groups like the Kiwanis Down Syndrome Foundation and the Down Syndrome Association of Malaysia are non-governmental organisations (NGOs) that provide care, education and early intervention programmes for children with Down Syndrome and their parents.

These support groups are heavily dependent on public donations.

It is time that the Health Ministry increases its support, particularly financial, to these organisations, especially when the ministry has a budget for rare diseases, which are less common than Down Syndrome.

Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth@thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.