Congenital abnormalities Flashcards
What is neural tube defect?
Impaired closure of the neural plate, at 3 weeks post conception, resulting in disability
Which supplement should mothers take to avoid neural tube defects in child?
folic acid
List two types of neural tube defect
anencephaly
encephalocele
microcephaly
spina bifida
Which neural tube defect is fatal?
anencephaly= scalp, skull, and cerebral hemispheres do not develop
Two symptoms of microcephaly?
shallow sloping head
developmental delay
seizures
short stature
Two causes of microcephaly?
genetic
maternal substance abuse
perinatal hypoxia
TORCH infections
What are TORCH infections?
(T)oxoplasmosis, (O)ther Agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes Simplex
What is the cause of cleft lip and palate?
failure of fusion of maxillary processes
What is the incidence of cleft lip?
1/1000
At what period is the cleft lip repaired?
3 months
At what age is the palate repaired?
6-12 months
Why is it important to repair cleft lip and palate?
speech problems
psychological issues
aspiration pneumonia risk
Is a preauricular pit concerning?
weak association with renal abnormalities
Is a preauricular tag worrying?
not at all, perhaps cosmetically
How is tracheo-oesophageal fistula diagnosed?
bronchoscopy and contrast studies of oesophagus
What is the presentation of tracheo-oesophageal fistula?
coughing, choking during feeding, abdominal distension, recurrent chest infections
Which condition is associated with duodenal atresia
down’s syndrome (1/3)
Which is a sign of duodenal atresia on AXR?
double-bubble
What is the most common presentation of duodenal atresia?
bilious vomiting shortly after birth
What is the prognosis of biliary atresia?
excellent with surgical management
What is exomphalos?
hernia to the base of the umbilical cord covered by a sac
Name one associated condition with exomphalos
trisomy 13, 18, and cardiac defects
Can exomphalos be surgically repaired in one go?
may need to be done in stages, as the abdomen is often too small
to hold the bowel
What is gastroschisis?
Defect in abdomen to the right of the umbilicus with protrusion of abdominal
contents not covered by a sac. The bowel is often in poor condition and may need to
be resected as part of the surgical repair. In contrast to exomphalos which has sac covering bowel.
What is hypospadias?
urethral opening on underside of penis
Is circumcision advised in hypospadias?
no as foreskin is used in the repair
When is surgery for hypospadias performed?
12-18 months
On which side does diaphragmatic hernia most commonly present?
90% on left side
Two presentations of diaphragmatic hernia?
dextrocardia, respiratory distress at birth, scaphoid abdomen?
What is achondroplasia?
bone growth disorder that is the most common type of dwarfism
What is the mode of inheritance of achondroplasia?
AD, mostly associated with spontaneous mutations
Two features of achondroplasia at birth?
short limbs, large heard flat midface, lumbar lordosis, trident hand
What is syndactyly and polydactyly?
synd= webbed fingers or toes polydact= >5 fingers or toes
What is the screening for down’s in the first trimester?
beta hCG, PAPP-A, age= calculation for risk
Which imaging can help to determine risk of down’s?
a raised foetal nuchal transluscency
Which investigations are offered to high risk mothers?
amniocentesis and chorionic villus sampling
What is the risk associated with amniocentesis and CVS?
amniocentesis= 1% risk of miscarriage CVS= 1.5% risk
List three facial features of down’s syndrome
- Prominent epicanthic folds
- Upward slanting palpebral fissures
- Brushfield spots on iris (white spots)
- Protruding tongue, with small mouth
- Small chin, flat nose, round face and small low set ears
Which is the most commonly associated condition with down’s syndrome?
congenital heart disease (50%)
Which is the most common congenital heart defect in down’s syndrome children?
atrioventricular septal defect
Name two GI defects in down’s syndrome
- Increased risk of Hirschprung’s disease.
- Increased risk of duodenal atresia and imperforate anus.
- High incidence of umbilical hernia
- High incidence of gastro oesophageal reflux
- Coeliac disease common
List two findings that you might see on physical exam on down’s syndrome patient
- Generalised Hypotonia
- Short neck with excess skin at nape
- Brachycephaly
- Single palmar crease, short hands and fingers and a sandal toe gap in feet
- Poor growth and short stature.
List two neurological complications of down’s syndrome?
- Learning Difficulties
- Hearing impairment (recurrent otitis media)
- Strabismus, cataract (require regular vision and hearing checks)
- Increased incidence of epilepsy
- Atlanto-axial instability – affects 10-20%, may cause spinal cord compression
Aside from neuro, GI, cardiac, list two complications of down’s syndrome, e.g. hypothyroidism
- Significantly raised incidence of haematological malignancy i.e. AML and ALL.
- Hypothyroidism – annual TFTs
- Recurrent respiratory infection
- Obstructive sleep apnoea
- Alzheimer’s disease
Define atresia
Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent.
What is the incidence of down’s syndrome?
1/1000
Name two mechanisms that result in down’s syndrome
non-disjunction (90%)
translocation
mosaicism
Which trisomy is Edward’s syndrome?
trisomy 18
Name two features of Edward’s syndrome
- Microcephaly, small chin
- Low set ears
- Overlapping fingers (thumb across palm, index over middle, little over ring)
- Rocker bottom feet
- Cardiac: VSD, ASD PDA.
What is the prognosis of edward’s syndrome?
most babies do not live beyond 1 year
Which trisomy is Patau’s syndrome?
trisomy 13
Name two features of patau’s syndrome
- Holoprosencephaly
- Structural eye defects
- Polydactyly
- Cutis aplasia (skin defects)
- Cardiac and renal defects
What is the prognosis of patau’s syndrome?
90% die in first year of life
Name two features of Turner
- Downward-turned mouth, downward slanting palpebral fissures
- Webbed neck, wide spaced nipples, lymphodema.
- Coarctation of aorta
- Streak gonads, lack of secondary sexual development
- Short stature
What is the chromosomal abnormality in Turner’s syndrome?
45XO
Two features of Klinefelter’s syndrome?
- Infertility
- Hypogonadism, microorchidism.
- Gynaecomastia
- Tall stature
- Intelligence from normal to moderate learning difficulties.
2 features of fragile X syndrome?
- Long face, prominent ears, large chin.
- Learning difficulty.
- Macroorchidism
- Connective tissue problems such as flat feet, hyperflexible joints
- Behavioural characteristics, autistic behaviours, hand flapping, ADD.
What is the chromosomal abnormality in Klinefelter’s syndrome?
XXY
Name three infections that cause congenital defects secondary to intrauterine infection
TORCH (Toxoplasmosis, Other (syphilis) Rubella, Cytomegalovirus, Herpes simplex
virus)
Define congenital
(of a disease or physical abnormality) present from birth.
List two features of congenital cytomegalovirus infection
- Low birth weight, microcephaly, cerebral calcification.
- Hepatosplenomegaly with jaundice
- Petechiae
What is the treatment for cytomegalovirus infection?
gancyclovir
List two complications of CMV infection
At risk for hearing loss, mental retardation, psychomotor delay, cerebral palsy, and
impaired vision
List two features of congenital rubella syndrome
- Cataracts, microphthalmos
- Sensorineural hearing loss
- Thrombocytopenic purpura “Blueberry muffin rash”
- Cardiac: pulmonary artery stenosis or patent ductus arteriosus.
- Hepatomegaly
List two features of congenital toxoplasmosis
- Hydrocephalus/ or microcephaly
- Chorioretinitis
- Cerebral calcification
- Cerebral palsy
- Epilepsy
List three features of foetal alcohol syndrome
- Microcephaly
- Facial features: epicanthic folds, low nasal bridge, absent philtrum, thin upper lip,
and small chin - Cardiac defects, VSD, ASD
- Growth retardation, limb abnormalities
- Learning difficulties and behavioural problems
List three teratogenic drugs
Phenytoin Sodium valproate Lithium Warfarin Tetracycline
What is the teratogenic effect of phenytoin?
Cleft lip/palate, cardiac defects, hypoplastic nails and craniofacial
abnormalities (called Foetal hydantoin syndrome)
What is the teratogenic effect of sodium valproate/carbamazepine?
neural tube defects
What is the teratogenic effect of lithium?
Ebstein’s anomaly
What is the teratogenic effect of warfarin?
frontal bossing, cardiac defects, microcephaly, nasal hypoplasia and
epiphyseal stippling.
What is the teratogenic effect of tetracyline?
discoloration of teeth
What is Ebstein’s anomaly?
In this condition, your tricuspid valve is in the wrong position and the valve’s flaps (leaflets) are malformed. Variability in severity
Name two physical features of prader wilii syndrome
almond shaped eyes, pale skin and light hair, small hands
and feet with hypogonadism
List two features of prader willi syndrome
- At birth - hypotonia, feeding problems, hypogonadism
- Later failure to thrive, scoliosis
- Hyperphagia and obesity
- Developmental delay and learning difficulties
Which chromosome is abnormal in Prader Willi Syndrome?
15
Name three maternal conditions/factors that can influence foetal development
diabetes, hyperthyroidism, alcohol, opiates & smoking
