Paediatric Genetics Flashcards
what dysmorphic features are associated with Down’s syndrome?
- hypotonia
- brachycephaly (small head with a flat back
- prominent epicanthic folds
- upward sloping palpebral fissures
- single palmar crease
- short neck and stature
- flattened face and nose
what are the complications of Down’s syndrome?
- learning difficulties
- recurrent otitis media
- deafness
- visual problems
- hypothyroidism
- cardiac defects, particularly ASD, VSD, PDA, TOF
- atlantoaxial instability
- leukaemia
- dementia
How to diagnose a rare intellectual disability +/ or malformation syndrome
- history
- description of dysmorphia: position and shape of facial features, hands, growth of child, general features
- recognition of patterns
Testing: - standard: biochemical, chromosome structure, microarray
- targetted testing
- moving to trio-based exome/genome
fetal akinesia sequence:
- reduced fetal movement
- reduced breathing
- contractures
- clefting
- lung hypoplasia
describe deformation and disruption
- pattern of development normal to start with but becomes abnormal
- deformation: organ parts are there
- disruption: parts of organ/body part absent
- e.g. amnitoic bands
An association is when two features or more occur together more often than expected by chance.
Describe the VATER association.
- Vertebral/VSD
- Anorectal atresia
- Tracheo-
- Eosophageal fistula
- Radial anomalies
what is a syndrome?
- a distinct group of symptoms and signs which, associated together, form a characteristic clinical picture or entity.
- cause may or may not be known
describe turner syndrome
- occurs when a female has a single X chromosome, making them 45 XO. The O refers to an empty space where the other X chromosome should be.
Clinical features of Turner syndrome
- short stature
- webbed neck
- high arching palate
- downward sloping eyes with ptosis
- broad chest and widely spaced nipples
- cubitus valgus
- underdeveloped ovaries with reduced function
- late or incomplete function
- most women are infertile
Turner’s syndrome associated conditions
- recurrent otitis media
- recurrent UTI
- coarctation of aorta
- hypothyroidism
- hypertension
- obesity
- diabetes
- osteoporosis
- various specific learning difficulties
Turner’s syndrome management
- Growth hormone therapy can be used to prevent short stature
- Oestrogen and progesterone replacement can help establish female secondary sex characteristics, regulate the menstrual cycle and prevent osteoporosis
- Fertility treatment can increase the chances of becoming pregnant
Patients need monitoring for the associated conditions and complications. Treatable conditions such as hypertension and hypothyroidism should be managed appropriate.
DiGeorge syndrome clinical features
CATCH:
- Cleft palate
- Abnormal facies
- Thymic hypoplasia/immune deficiency
- Calcium
- Heart problems
- 22q11 deletion
what does karyotyping involve and what conditions is it useful in diagnosing?
- involves looking at the no. chromosomes, their size and basic structure
- helpful in diagnosing Down’s syndrome and Turner Syndrome.
