Patients with Down syndrome (DS) require continuous access to quality health #InclusiveHealth. Approximately 1 out of every 800 babies are born with Down syndrome worldwide. They have three, instead of two, copies of chromosome 21. This cannot be seen but the dysmorphic physical characteristics, inclusive of the flat nasal bridge, prominent epicanthal folds, and a single, prominent palmar crease are usually apparent.

Down syndrome is the most common chromosomal condition associated with intellectual disability. Despite this, most children with DS can learn basic tasks even if they take longer than other children to master these. Since people with DS have the potential for development and socialisation they need to be adequately supported to ensure social integration.  

Common associated medical conditions

People with DS are plagued by a range of coexisting medical conditions, some of these require immediate management at birth and others lifelong surveillance.

Most children with Down syndrome experience problems with vision and hearing. Other associated medical conditions with a high incidence include congenital heart disease (mostly septum defects, i.e. defects in the walls separating the chambers of the heart), neurological problems and immunodeficiency.

Haematological disorders

Of particular interest to us in the Department of Haematology are the related haematologic and oncologic disorders. Approximately 10% of neonates with DS develop a haematologic disorder called transient leukaemia of Down syndrome or transient abnormal myelopoiesis, which is clinically indistinguishable from acute myeloid leukaemia in children with DS. While this disorder resolves spontaneously over weeks to months, 20-23% of patients affected will develop acute myeloid leukaemia within four years.

People with DS have an increased risk (10 and 100-fold) of developing leukaemia. The risk of leukaemia extends into adulthood. Children less than 5-years with DS have an approximately 150-fold increase in acute myeloid leukaemia. Peculiarities of these myeloid leukaemias associated with Down syndrome include that they often follow a prolonged myelodysplastic syndrome-like phase and acute megakaryoblastic leukaemia predominates. The latter means that blood cancer originates from the cells responsible for the production of blood platelets. We recently diagnosed a 7-month-old patient with DS with this disorder in our department. The prognosis is dependent on the underlying molecular abnormality but it is generally favourable in that children with DS responds better to treatment than children without DS. Recent research has focused on attempts to reduce treatment-related morbidity and mortality which is significant in this group of patients. Reduced-intensity chemotherapeutic regimens have shown promising results and precision medicine strategies should be employed to improve outcomes for these patients

The disparity in access to health care and other supportive resources still exists. 21 March is World Down Syndrome Day. Play your part to ensure full and effective participation and inclusion of patients with Down syndrome in society. To connect and participate please visit the links below:

https://www.downsyndrome.org.za/ 

https://www.ds-int.org/Event/world-down-syndrome-day-programme-2022?gclid=Cj0KCQjwuMuRBhCJARIsAHXdnqOe5ywW9lM84Rg1JfHyadwH7hkpIGZVWDSASH5AvwAt855CXI5HHTIaAtEAEALw_wcB

References:

Tomizawa D, Kolb EA. Down syndrome and AML: where do we go from here? Blood 2017; 129 (25): 3274–3275. doi: https://doi.org/10.1182/blood-2017-04-780031

Tunstall O, Bhatnagar N, James B, Norton A, O'Marcaigh AS, Watts T, et al. British Society for Haematology. Guidelines for the investigation and management of Transient Leukaemia of Down Syndrome. Br J Haematol. 2018 Jul;182(2):200-211. doi: 10.1111/bjh.15390. Epub 2018 Jun 19. PMID: 29916557.

Bull MJ. Down Syndrome. N Engl J Med 2020; 382:2344-2352.

Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, et al (Eds) (2017) WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. 4^th Edition. IARC, Lyon.