Syndromes / Genetics Flashcards
What is the inheritance of achondroplasia?
Autosomal Dominant
Turner’s Syndrome - genetics
45 XO (Monosomy) [50%] - affects girls
Mosaicism or Abnormal partial X or Y chromosome [50%]
SHOX-gene: affects growth + maturation of skeleton
UTX-gene: immunodeficiency -> recurrent otitis media
TIMP-1 + TIMP-3: Cardiac defects
Angelman Syndrome
1) What is it ?
2) Genetics ?
1) Rare genetic condition that affects the nervous system and causes severe physical and learning disabilities:
Presents:
- Severe developmental delay (6-12 months)
- little or no Expressive language
(preserved maintenance for social interaction)
- Ataxia
- Hypermotor behaviours
- Happy demeanour.
2) Uniparental inheritance - Chq11
Loss of Maternal UBE3A-gene in the brain.
Di George Syndrome: genetics & inheritance
Micro deletion of Ch-22 (Ch-22q11) - TBX1 gene
Autosomal Dominant
What are the features of DiGeorge syndrome:
[CATCH-22]
C-Cleft Palate: 3rd + 4th Pharyngeal arch defects
A - Abnormal facies
long narrow face, low set ears, narrow eyes
T - Thymic hypoplasia -> immunodeficiency
(Impaired T-cell formation + function)
C - Cardiac: TOF, VSD , AVSD
H - Hypocalaemia -> hypoparathyroidism (Neonates)
Renal tract abnormalities
Scoliosis
Learning difficulties
Downs Syndrome: genetics
47XX or 47XY Trisomy 21 [T21]
1) Meiotic Non-disjunction [94%] 1:100 Maternal age <35
2) Robertsonian-Translocation (Ch14 - Ch22) [5%]
3) Mosaicism [1%] - Mitotic Non-disjunction
Features of Down’s Syndrome [T21]
Prader-Willi Syndrome: genetics & inheritance
Paternal Ch-15q13 deletion [70%]
Maternal uniparental disomy [25%]
Imprinting defect [5%]
Prader-Willi syndrome: features [8]
Neonatal Hypotonia
Feeding difficulties: increased sticky saliva production
Obesity: Increased Appetite
- OSA
- Osteoporosis
Short Stature
Hypogonadism:
Behavioural/learning difficulties
Abnormal Facies:
- Narrow Forehead
- Almond Eyes
- Thin upper lip
Small hands + Feet
Turners Syndrome [45XO]: Dysmorphic Features
Epicanthic Folds
Short Webbed Neck
Short Stature
Wide Spaced Nipples
Low Hairline
Low-set posteriorly rotated ears
What is Sturge-Weber syndrome?
Neuro cutaneous disorder:
1) Cutaneous lesions: port wine stain
2) CNS abnormalities
3) Ocular abnormalities
What affected ocular nerve causes port-wine stain in Sturge-Weber
Trigeminal Nerve
What is the inheritance of Von Willebrand’s disease?
Autosomal dominant
What is the inheritance pattern for Marfan’s syndrome
Autosomal Dominant
What is the inheritance pattern for Neurofibromatosis?
Autosomal dominant
What is the inheritance pattern for Tuberous Sclerosis?
Autosomal dominant
What is the inheritance of osteogenesis imperfecta?
Autosomal dominant
What is the inheritance of Hunter syndrome
X linked recessive
What are the clinical signs of SOTOS Syndrome ?
1) Cerebral gigantism [Macrocephaly]
2) Large hands + feet
3) Thickened Subcutaneous Tissue
4) Developmental delay
What is Incontinentia Pigmenti?
a) Inheritance / genetics
b) Clinical features
c) Investigations
d) Management
What is Ehlers-Danlos syndrome [EDS]:
a) Inheritance / genetics
b) Clinical features
c) Investigations
d) Management
Neurofibromatosis type 1 [NF1]
a) Inheritance / genetics
b) Clinical features
c) Investigations
d) Management
Tuberous Sclerosis complex:
a) Inheritance / genetics
b) Clinical features
c) Investigations
d) Management
Hypohydrotic ectodermal dysplasia:
a) Inheritance / genetics
b) Clinical features
c) Investigations
d) Management
What is Bartter’s Syndrome?
(Inheritance / genetics)
Rare - 1:1,000,000
Type 1 - *SLC12A1* [AR] Type 2 - *ROMK1* [AR] Type 3 - *CIC-Kb* [AR] Type 4 - *CIC-Ka / CIC-Kb* [AR] Type 5 - *MGED2* [X-linked recessive] Hypocalaemic Hypercalciuria - CaSR [AD]
Defective function of the Na+/K+/2Cl- co-transporter in the Thick ascending loop of Henle, affects renal tubular function which leads to
- LOW K
-ALKALOSIS
HYPOTENSION
What are the characteristics biochemical changes seen in Bartter’s syndrome
Blood:
Metabolic Alkalosis
- hypokalaemia
- hyponatraemia
- hypochloraemia
- hypocalcaemia [Type 5]
- (H) Renin & Aldosterone levels
Urine:
- hypercalciuria
- hyperchloruria
Clinical Presentation of Bartter’s syndrome? (Antenatal)
Antenatal [Type 1, 2, 4, 5]:
- Polyhydramnios
- / + Prematurity
Clinical Presentation of Bartter’s syndrome? (Neonatal)
Neonatal [Type 3]
Dysmorphic features:
- triangular facies
- protruding ears
- large eyes
- strabismus
- drooping mouth
Severe salt-wasting:
- dehydration
- hypotension
Clinical Presentation of Bartter’s syndrome? (Childhood) [7]
Recurrent polyuria with dehydration
Faltering growth
Fatigue
Dizziness
Chronic constipation
Muscle cramps + weakness (2o - hypokalaemia)
BP - normal
Renal function - normal
Nephrocalcinosis (2o - hypercalciuria)
What is the inheritance pattern & genetics of Friedrich’s Ataxia?
1) Autosomal-Recessive [AD]
2) Tri-nucleotide repeat expansions in “Frataxin” mitochondrial protein
What the inheritance & genetics for Fragile-X syndrome
X-linked, stable inherited tri-nucleotide repeats in FMR1-gene
Spinocerebellar Ataxia (SCA 7)
Autosomal Dominant [AD]
Trinucleotide repeat patterns
Huntingtons Disease
Autosomal Dominant with trinucleotide repeated pattern
Which genes is implicated in Tuberous Sclerosis?
TSC1 - Hamartin
TSC2 - Tuberin
Loss of inhibition within the mTOR-pathway leads to growth of hamartomas, within these organs below:
- Skin
- Brain
- Kidney
- Lung
- Heart
What are the Neuro-cutaneous manifestations of Tuberous Sclerosis? [3]
1) Shagreen patches
2) Ash-leaf macules
3) Periungual fibromas
What percentage of children with
Turner’s syndrome have co-arctation of the aorta ?
30-50%
Neonates/Infants, who present with Severe co-arctation should be tested for chromosomal abnormalities:
Eg: Turners 45XO
What are the causes of congenital adrenal hyperplasia [CAH] ? (3)
[Karyotype: 46 XX,
1) 21-hydroxylase deficiency
2) 5-alpha-reductase deficiency
3) 11-beta-hydroxalase deficiency
What is 5-alpha-reductase deficiency?
- which population
- karyotype
Enzyme deficiency, which causes androgen insensitivity
- Dominican Republic
- 46 XY
11-beta-hydroxylase deficiency
Enzyme deficiency leading to:
Congenital Adrenal
What lung pathology associated with Congenital Diaphragmatic Hernia?
Pulmonary Hyoplasia:
Compromised development of the Lung-tissue due to abnormal intestinal position in the chest.
- Respiratory Distress
- Cardiovascular Compromise
Signs of Congenital CMV ? [5]
IUGR
Microcephaly
Intraventricular calcification
Chorioretinitis
Sensorineural Deafness
Signs of Congenital HSV ? [3]
Microcephaly
Cutaneous Scars
Vesicles
Signs of Congenital Rubella ? [5]
Cardiac Defects
Cataracts
Hepatosplenomegaly
Microcephaly
Petechiae
Signs of Congenital Syphilis ? [3]
Coryzal
Hepatosplenomegaly
Rash
Signs of Congenital Toxoplasmosis ? [4]
IUGR
Hydrocephalus
Intercerebral calcification
Chorioretinitis
Secondary Apnoea Phase?
Loss of Spontaneous Breathing
Rapidly Worsening acidosis
Impaired Cardiac function
(Babies in this phase will likely require chest compressions in addition to respiratory aeration]
Which Maternal Hormone plays a significant role in successful fetal-newborn transition ?
Cortisol: Major regulatory hormone for Terminal Maturation & Adaptation at birth.
- Lung Maturation
- Lung fluid clearance
- Thyroid Axis Maturation
- Catecholamine release
- Raised B-receptor density
Treatment for neonatal chickenpox [VZV] within 7days?
Varicella Zoster Immunoglobulin (VZ-IG)
What are the Neurological features of Sturges-Weber syndrome?
- Epilepsy —> Siezures
- Mental retardation
- Stroke-like illness
- Developmental delay
What are the
What are the Occular manifestations of Sturge-Weber syndrome?
Glaucoma
Buphtalmos
Vascular lesions:
- Conjunctiva
- Episclera
- Choroid
- Retina
What skin lesion is indicative of Sturge-Weber syndrome?
Port wine stain [PWS]:
“Erythematous macular lesion”
Trigeminal Nerve distribution:
- Opthalmic branch
- Maxillary branch
What cranial changes may you find in Sturge-Weber syndrome?
Intracranial “Tramline calcification”
What Neurovascular changes seen in Sturges-Weber syndrome?
Leptomeningeal Angiomata
Protruding tongue
Hypotonia
Frog position legs
Who am I???
Glycogen storage disease type 2
What enzyme is missing in glycogen storage disease
Acid alpha glucosidase
Means glycogen can’t be broken down
No glucose
No energy for muscles
They don’t work properly
In infants - this includes the heart
Baby can’t move his left arm held in extended position
Some may call it pseudoparalysis of parrot
What disease you thinking
Congenital syphilis
Initial investigation for congenital syphilis
Serum rapid plasma regain
Treponemal IgA