Paediatric Childhood syndrome Flashcards
Down’s syndrome - Pathophysiology
- Trisomy 21 - extra Chromosome 21
- Majority causes by non disjunction during maternal meiosis I
- Leads to formation of gamete with extra Chromosome 21
- Clinical features are caused by over-expression of genes on chromosome 21
Down’s syndrome - Physical clinical features
Face
1. Eyes
* Epicanthic folds
* Brushfield spots on iris
- Flat Occiput, low set ears
-
Limbs
* Single palmar crease
* ’Sandal gap’ - Big - First toe
* Hypotonia - Short stature
- Obesity
Down’s syndrome - Clinical complications
1 . Congential heart disease : AV septum defect most common
2 . GI
*Duodenal atresia
* Hirschsprung’s disease
3 . Subfertility
4 . Recurrent Otitis media
5 .Hypothyroidism
6 .Acute lymphoblastic leukaemia
7 .Alzheimer’s disease : over expressed of APC gene due to extra chromosome 21
Down’s syndrome : Main risk factor
Advancing maternal age
Patau syndrome : Definition
** Trisomy 13 : Extra chromosome 13**
Patau syndrome : Clinical features
- P - Polydactyly- extra fingers or toes.
-
A - Abnormal CNS (Central Nervous System):
* Microcephaly - T - Trisomy 13
-
A - Abnormal facial features
* Cleft lip and palate - U - Underdeveloped eyes (Microphthalmia) - small eyes
Edward’s syndrome : Definition
Trisomy 18 : Extra chromosome 18
Edward’s syndrome : Clinical features
- E: eighteen (trisomy 18)
- D: digit-overlapping flexion
- W: wide head
- A: absent intellect (mental retardation)
- R: rocker-bottom feet
- D: diseased heart
- S: small lower jaw
- Fragile X syndrome : Pathophysiology
- X linked inheritance
- Mutation of FMR1 gene due to expansion of trinucleotide repeat sequence - causing it to be silenced
- More repeats, the more severe
- FMR gene is important for brain development
- Fragile X syndrome : Clinical features
‘e X tra large testes, jaws, and ears’
1. Learning difficulties
1. Macrocephaly
1. Long face
1. Large ears
1. Macro-orchidism
- Noons syndrome : Pathophysiology
- Sporadic mutation
- Genetic mutation in RAS-MAPK signalling pathway (regulates cell growth and differentiation) which causes dysregulation of development and organ function.
Noons syndrome : Clinical features
** The SUN BURNS at NOON!**
Short stature
Unusual facies (Ocular hypertelorism, low set ears)
Neck is webbed
Bleeding disorders
Unusual chest shape - Pectus excavatum
RAS MAPK mutation
Nose is flat
Stenosis (Pulmonic stenosis)
Pierre-Robin syndrome : Pathophysiology
- Position in utero : compression of lower jaw against chest during fatal development
Pierre-Robin syndrome : Clinical features
- Underdeveloped mandible : small jaw
Leads to ;
* Retracted tongue : limited space for tongue causing it to be positioned further back } Respiratory distress when supine
* Cleft palate
Prader-Willi syndrome : Definition
** Deletion of genes on paternal Chr 15 **
- Prader-Willi syndrome : Pathophysiology
- Deletion of genes on paternal Chr 15
- These genes play role in development and function of the hypothalamus
- Clinical features are secondary to hypothalamic dysfunction
- Prader-Willi syndrome : Clinical features
Clinical features are secondary to hypothalamic dysfunction -> metabolic and hormonal dysregulation
- Hyperphagia and obesity : hypothalamus unable to regulate appetite.
- Short stature : Growth hormone deficiency
- Hypogonadism : Lack of sex hormone release
- Hypotonia : CNS motor development abnormality
William’s syndrome : Definition
- **Deletion of genes on Chr 7 **
* Elastin gene is effected : which is important for tissue development particularly the heart
William’s syndrome - Clinical feature
- Weight (low at birth, slow to gain)
- Iris (stellate iris) -‘Bicycle wheel pigment’ of iris
- Long philtrum
- Large mouth
- Increased Ca++ } transient neonatal hypercalcaemia
- Aortic stenosis (Supravalvular)
- Mental retardation
- Short stature and sweet (friendly personality
- /William has 7 letters = Chromosome 7/*
Cri du chat syndrome : Pathophysiology
Partial deletion of genetic material on short arm of Chromosome 5.
The deleted genetic material played a significant role in
- Communication and development of vocal chords/Larynx : thus non verbal and ‘cat like cry’
- Cognitive and craniofacial development
Cri du chat syndrome : Clinical features
- **C **- Cat-Like Cry
- R - Round Face
- I - Intellectual Disability
- D - Developmental Delays
- U - Unusual Facial Features
- C - Communication Difficulties
- H - Hypertelorism (Wide-Set Eyes)
- A - Aggression (Behavioral Challenges)
-
T - Tiny Jaw (Micrognathia)
1.** S** - Small Head Size (Microcephal
