Downs_Syndrome_Features_Flashcards
What are the facial features of Down’s Syndrome?
Facial features include upslanting palpebral fissures, epicanthic folds, Brushfield spots in the iris, protruding tongue, small low-set ears, and a round/flat face.
What are some physical features of Down’s Syndrome?
Physical features include a flat occiput, single palmar crease, pronounced ‘sandal gap’ between the big and first toe, and hypotonia.
What are common congenital conditions associated with Down’s Syndrome?
Common congenital conditions include heart defects (40-50%), duodenal atresia, and Hirschsprung’s disease.
What are the common cardiac complications in Down’s Syndrome?
Cardiac complications include endocardial cushion defect (40%), ventricular septal defect (30%), secundum atrial septal defect (10%), tetralogy of Fallot (5%), and patent ductus arteriosus (5%).
What are later complications associated with Down’s Syndrome?
Later complications include subfertility, learning difficulties, short stature, repeated respiratory infections, acute lymphoblastic leukaemia, hypothyroidism, Alzheimer’s disease, and atlantoaxial instability.
summarise
Down’s syndrome: features
Clinical features
face: upslanting palpebral fissures, epicanthic folds, Brushfield spots in iris, protruding tongue, small low-set ears, round/flat face
flat occiput
single palmar crease, pronounced ‘sandal gap’ between big and first toe
hypotonia
congenital heart defects (40-50%, see below)
duodenal atresia
Hirschsprung’s disease
Cardiac complications
multiple cardiac problems may be present
endocardial cushion defect (most common, 40%, also known as atrioventricular septal canal defects)
ventricular septal defect (c. 30%)
secundum atrial septal defect (c. 10%)
tetralogy of Fallot (c. 5%)
isolated patent ductus arteriosus (c. 5%)
Later complications
subfertility: males are almost always infertile due to impaired spermatogenesis. Females are usually subfertile, and have an increased incidence of problems with pregnancy and labour
learning difficulties
short stature
repeated respiratory infections (+hearing impairment from glue ear)
acute lymphoblastic leukaemia
hypothyroidism
Alzheimer’s disease
atlantoaxial instability
A 38-year-old woman gives birth to a baby boy. On initial examination he is noted to have poor tone and further examination reveals features of Down’s syndrome. Which one of the following features is he least likely to have?
Single palmar crease
Sandal gap
Brushfield spots
Rocker-bottom feet
Epicanthic folds
This question focuses on the features of Down’s syndrome. This is an important topic to know for clinical practice and for final examinations. In this case, answer 4 is correct. Rocker-bottom feet are characteristic of trisomy 18 or Edward’s syndrome, but are not commonly seen in Down’s syndrome.
A 36-year-old primigravida attends an antenatal clinic appointment at 17+0 weeks gestation for amniocentesis following a high-risk combined screening test. The results of this test show trisomy 21.
What is a late complication of this disease?
Alzheimer’s disease
Chronic myeloid leukaemia
Hirschsprung disease
Hyperthyroidism
Tetralogy of Fallot
Alzheimer’s disease
Down syndrome - Alzheimer’s disease
Importance: 39
The correct answer is Alzheimer’s disease (AD). This is a late complication of Down’s syndrome. People with Down’s syndrome are born with an extra copy of chromosome 21, which carries a gene that produces a specific protein called amyloid precursor protein (APP). Too much APP protein leads to a buildup of protein clumps called€¯beta-amyloid plaques€¯in the brain. By the age of 40, most people with Down’s syndrome have these plaques, along with other protein deposits, called tau tangles, that further increase the risk of developing AD.
Acute lymphoblastic leukaemia(ALL) is a late complication of Down’s syndrome - making chronic myeloid leukaemia incorrect. ALL may present as repeated infections, unusual and frequent bleeding, night sweats, bone and joint pain, or easily bruised skin.
Hirschsprung disease is a birth defect where nerve cells are missing from parts of the large intestine, resulting in severe constipation and sometimes intestinal obstruction. It is more common in babies with Down’s syndrome. However, this would be classed as an early complication.
Similarly, hypothyroidism is a late complication of Down’s syndrome, usually caused by an autoimmune reaction - making hyperthyroidism incorrect. Hyperthyroidism occurs very rarely.
Tetralogy of Fallot is a potential complication of Down’s syndrome, however it would be present from birth, so is not a late complication. This heart defect involves four features: pulmonary stenosis, a ventricular septal defect, right ventricular hypertrophy, and an overriding aorta.
