Demystifying Down syndrome

During a symposium with mothers of children with Down syndrome, Dr Nandini Gokulchadran, a consultant neurosurgeon and head of medical services at NeuroGen Brain and Spine Institute in Mumbai, India, defined Down syndrome as a common genomic disorder of intellectual disability in which an individual has full or partial extra copy of Homo sapiens chromosome 21(HSA21). 

Julius Oyeyo, an occupational therapist at Tunaweza Children’s Home, stresses the fact that this is not a disease but a genetic anomaly. Therefore, it is only managed and cannot be treated.

Most times, he adds, the error in the chromosome occurs randomly during the formation of egg and sperm cell and no behavioural or environmental factors are known to cause Down syndrome.

Symptoms

Individuals with Down syndrome commonly have a short stature, muscle hypotonia (poor muscle tone), atlantoaxial instability (the connections between muscles (ligaments) are “lax” or floppy), reduced neuronal density, cerebellar hypoplasia (cerebellum is smaller than usual or not completely developed), intellectual disability, and congenital heart defects.

Other signs include a flattened face, small head, short neck, protruding tongue, upward slanting eye lids (palpebral fissures), unusually shaped or small ears, broad, short hands with a single crease in the palm, relatively short fingers and small hands and feet, excessive flexibility, and tiny white spots on the coloured part (iris) of the eye called Brushfield’s spots.

Diagnosis

Dr Nandini says a Down syndrome diagnosis prenatally can be done in two ways. One is through a screening test, which includes blood test (invasive test) and an ultrasound test (non-invasive). The other is through a diagnostic test, which includes amniocentesis and chorionic villus sampling.

READ: Our son was diagnosed with Down Syndrome

It can also be diagnosed at birth or during early infancy, based on physical characteristics such as low muscle tone, a small head, ears and mouth, upward slanting eyes, and irregular spacing between the toes.

What does it mean to be born with Down syndrome?

Down syndrome affects an individual’s ability to think, reason, socialise or understand some things. Dr Nandini says the effect varies from person to person but includes: 

● Delayed crawling, walking and talking milestones.

● In school, they may need extra help reading, writing or command following due to delayed language and speech development. This causes slow learning.

● Affected short term or long term memory.

● Short attention span.

● Inability to manage their feelings when frustrated, thus impulsive behaviour.

● Require extra assistance for their daily activities.

● Poor judgment.

Related health conditions

Dr Nandini says persons with Down syndrome are most likely to have the following health conditions:

Heart problems: About 50 percent of people affected with Down syndrome have cardiac abnormalities such as atrioventricular septal defects (AVSDs) and they require surgical interventions.

Hearing loss: Many have hearing loss of one or both the ears often due to fluid build-up.

Ophthalmic problems: About three-quarters of children with Down syndrome have refractive problems such as myopia, or conditions such as cataract, nystagmus, blepharitis, strabismus or keratoconus.

Obstructive sleep apnea: This is a treatable condition where breathing stops and restarts many times while sleeping.

Interventions

Oyeyo says owing to the issues that persons with Down syndrome face, there is need for a lot of interventions to ease their lives. 

READ: Children with birth defects hit hard by Covid

Since most of these children delay to hit physical milestones such as sitting, crawling due to poor muscle tone, they need physiotherapy services for muscle strengthening and correcting their posture. Physiotherapy is more of exercise to help the muscles grow and become stronger.

Due to the nature of their structure, most have high arched palates thus poor word and sound pronunciations. That is why they need the help of a speech and language therapist to help them with phonation.

They also have issues with fine motor skills (movement and coordination of small muscle groups such as the fingers). These hand muscle groups are essential in daily activities. Therefore, functionally, they need the help of an occupational therapist to help them learn some self-care tips such as buttoning, brushing, playing, dressing and using the toilet. That also includes daily activities such as writing.

In regards to cognitive skills such as concentration, attention and memory, the occupational therapist alongside their teacher will help with these. That will enable them perform better in class and in daily life.

All in all, the practical intervention among people with Down syndrome depends on the challenges the child is presenting at the time of assessment. “While some may easily overcome the physical challenges, they may struggle with speech and vice versa. That is why assessment is important so that help given is well informed,” Oyeyo says.

What can we do better?

Down syndrome cannot be prevented, but parents can take steps that may reduce the risk. 

“The older the mother, the higher the risk of having a baby with Down syndrome. Women can reduce the risk of Down syndrome by giving birth before age 35,” Oyeyo advises.

Uptake of folic acid supplements consumption before conception is helpful. 

“Folate is an essential vitamin B and its pathway plays a critical role in cellular function and human development, as evidenced by the association between maternal folic acid high dose intake and the risk of neural tube defects (NTD). Dietary intervention studies show that genomic instability is minimised when the plasma folate level exceeds about 34 nmol/l and the plasma homocysteine (Hcy) level is less than 7.5 µmol/l. Hcy levels inversely indicate the folate and methyl folate in blood plasma. These levels can only be achieved when folic acid intake is above 5mg per day,” Dr Nandini says.

Pre-implantation genetic diagnosis: Dr Nandini says this is the safest means for a normal pregnancy for couples who had pregnancies with Down syndrome or for couples at high risk of transmitting a genetic defect. 

“It involves the screening of in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) generated embryos for the trisomy 21, fluorescence in site hybridisation (FISH) is used in this procedure. After confirmation of normal count of chromosomes, the embryo is then transferred to the womb,” she says.

Routine care

Many babies with Down syndrome deal with health problems such as:

Feeding difficulties: Learning to breastfeed or suck a bottle may take them longer to learn. Special training is required.

Heart defects: The doctor monitors the heart health until it is corrected, some heart problems will require surgery within the first year. Minor problems will correct themselves over time. 

Hearing issues: Some babies will have partial hearing loss due to having smaller Eustachian tubes (part of inner ear). This causes fluid build-up but can be relieved with tubes. Some babies have permanent nerve damage, which can cause permanent hearing loss. Hearing aids often help your child hear. Without treatment, the hearing loss can affect your baby’s speech development.

Vision problems: This might include cataracts or other eye issues requiring glasses.

Neck issues: Some also have issues with their neck where the first joint on the vertebra has issues in that the neck can easily fall back beyond normal. For one with this anomaly, when older, games such as football, and activities such as carrying heavy loads on the head must be avoided.

Older children

Prepare them for social interaction by telling or showing them social stories that can boost their confidence and help them prevent an emotional breakdown.

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