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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 5, September/October 2016
AFRICA
287
Congenital heart disease and Down syndrome: various
aspects of a confirmed association
Sanaa Benhaourech, Abdenasser Drighil, Ayoub El Hammiri
Abstract
Background:
Congenital heart disease (CHD) is frequently
described in patients with Down syndrome (DS) and is the
main cause of death in this population during the first two
years of life. The spectrum of CHD patterns in DS varies
widely worldwide; this variation could be due to sociodemo-
graphic, genetic and geographic factors.
Methods:
A six-year retrospective, descriptive study was
carried out from December 2008 to October 2014, based on
the Paediatric Unit CHD registry of Ibn Rochd University
Hospital. Clinical, echocardiographic and outcomes data
were collected and sorted according to confirmation of the
syndrome.
Results:
Among 2 156 patients with CHD, 128 were identified
with Down syndrome. The genders were equally represented
(gender ratio 1) and the median age at diagnosis was 9.5
months (2 days to 16 years). The median age of mothers
at delivery was 39 years (16–47). Of the 186 CHD lesions
reported, the most common was atrioventricular septal defect
(AVSD, 29%), followed by ventricular septal defect (VSD,
21.5%) and atrial septal defect (ASD, 19.9%). The most
common associations of CHD were AVSD
+
ASD (10%) and
VSD
+
ASD (7.8%). Surgery was the most common modality
of treatment (54.3%). The overall mortality rate was 14.1%.
Conclusion:
Our study confirmed that the profile and type
of CHD in DS in the Moroccan setting exhibited slight
differences in the distribution of these CHDs compared with
European neighbours and other Western countries. Further
studies are needed to determine which variables have an
impact on these differences.
Keywords:
Down syndrome, congenital heart disease, epidemiol-
ogy, therapeutic
Submitted 6/9/15, accepted 2/3/16
Cardiovasc J Afr
2016; 27: 287–290
www.cvja.co.zaDOI: 10.5830/CVJA-2016-019
Down syndrome (DS), which is caused by trisomy on
chromosome 21, is by far the most common and best known
chromosomal disorder in humans and the most common cause
of intellectual disability.
1-3
This trisomy gives rise to multiple
complications as part of the syndrome. Congenital heart disease
(CHD) is the leading cause of mortality and morbidity during
the first two years of life in the DS population,
1,4
and 40 to 63.5%
of DS patients have CHD.
4-6
It has been suggested that the profile and type of these CHDs
are variable according to the different geographical areas around
the world.
7,8
Recent studies in Norway also suggest a seasonal
variation in the occurrence of DS and birth defects, and provide
indirect evidence of the causal role of environmental factors,
since genetic factors do not exhibit seasonality.
9
BecauseMorocco
is bordered by European countries, it has been suggested that a
combination of local factors and regional proximity could play a
significant role in the CHD profile in the DS population.
However, in a given context, it is important to be familiar with
the incidence and anatomical characteristics of CHD in DS, as
well as the associated complications and causes of morbidity
and mortality, in order to apply preventative measures and to
improve the patient’s quality of life. In addition, because the
type of CHD and the timing of repair affect the prognosis,
timely treatment of cardiac abnormalities is crucial for optimal
survival.
10
The lack of reliable data from African countries is a
limiting factor in addressing the issue of geographical variations
around the world.
The reported rates of different features of CHDs inDS patients
between countries in close proximity are quite similar, such as
the USA and Mexico or other Latin-Americans countries.
3,4,8,11
This could be explained by regional proximity, which may have
a greater effect in instances of geographical areas with long-
standing populations, as is the case in the Mediterranean area.
Morocco is a North African country that has historical links
with European populations in the Mediterranean area, but also
with those of Africa in the south. This study sought to determine
the prevalence and profile of CHD in DS in the Moroccan
context and to compare this with the international literature.
Methods
This retrospective, descriptive, monocentric study was based
on the Paediatric Unit CHD registry of Ibn Rochd University
Hospital. All CHD-affected patients diagnosed with DS (with or
without chromosomal studies) during the period from December
2008 to November 2014 were included in the study.
Phenotypic clinical features matching with DS recorded in
the medical charts were as follows: mongoloid facies, protruding
tongue, transverse single palmar crease, brachycephaly,
depressed nasal bridge, small, low-set ears, and upward-slanted
eyes with epicanthic fold, short neck and hypotonia. General
characteristics such as gender, age of diagnosis and mother’s age
at delivery were also recorded.
The examinationprotocol during echocardiographic assessment
was as follows: subxiphoid imaging followed by a segmental
approach for description of the major cardiovascular structures
in sequence, with the image apex at the bottom of the video. We
recorded all videos of the examinations and all cases underwent
Cardiology Department, University Hospital Ibn Rochd,
Casablanca, Morocco
Sanaa Benhaourech, MD,
Sanaa_b19@hotmail.frAbdenasser Drighil, MD
Ayoub El Hammiri, MD