Inherited conditions Flashcards
Peutz-jeghers syndrome
An autosomal dominant condition with multiple GI polyps and pigmented freckles onthe lips, face, palms and soles. 50% of pts will die from GI Ca by 60yrs.
Gardner’s Syndrome
FAP
Hereditary Haemorrhagic telangectasia (osler-weber-Rendu syndrome)
Iron deficiency anaemia and mucocutaneous telangectasia. AN autosomal dominant but 20% of cases are spontaneous. May present with recurrent epistaxis, telagectasia in the skin or organs (AVMs)
Causes of downs and recurrence risk
94% - non-disjunction - 1/100 recurrence if mother is <35
5% - Robertsonian translocation - 10-15% if mother or 2.5% if father
Mosaicism - 1%
Patau syndrome (trisomy 13)
Microcephalic, small eyes
Cleft lip/palate
Polydactyly
Scalp lesions
Edward’s syndrome (trisomy 18)
Micrognathia (small jaw)
Low-set ears
Rocker bottom feet
Overlapping of fingers
Fragile X
Learning difficulties Macrocephaly Long face Large ears Macro-orchidism
Noonan syndrome
Webbed neck
Pectus excavatum
Short stature
Pulmonary stenosis
Pierre-Robin syndrome
Micrognathia
Posterior displacement of the tongue (may result in upper airway obstruction)
Cleft palate
Prader-Willi syndrome
Hypotonia
Hypogonadism
Obesity
William’s syndrome
Short stature Learning difficulties Friendly, extrovert personality Transient neonatal hypercalcaemia Supravalvular aortic stenosis
Treacher-collins syndrome
An autosomal dominant condition which presents very similarly to Pierre-robin syndrome
G6PD deficiency
Commonest RBC defect in african/mediterrean people. X-linked recessive. Crises linked to infections, drugs (ciprofloxacin, primaquine, sulpha containing drugs) or fava beans. Intravascular haemolysis and splenomegaly may be present. Also gallstones or heinz bodies on blood films.
Homocystiuria
A rare autosomal recessive metabolic condition characterised by increased blood/urine homocysteine. 50% are B6 responsive and milder. Abnormalities manifest with eye problems and mental retardation at 3-4yrs. May have a marfinoid body form + other abnormalities
Spina bifida
10% of the pop may have spina bifida occulta (where bones have not developed over the spinal cord) - identifiable by a birth mark or hair patch.
other forms are rarer because of folate supplementation.
Meningocele
Meningeal cyst is the least common form of spina bifida - where vertebrae form but the meninges are forced out of the gaps. They will rarely have long term health problems (may have tethered cord)
Myelomeningocele
A meningeal cyst containing spinal cord or nerves. This form has the most severe complications. Can lead to loss of bladder or bowel control. Partial or complete loss of sensation or paralysis of the legs. Can present as weakness of the hips, legs and feet of a newborn.
Myeloschisis
Like Myelomeningocele but without the membrane. Very high risk of infections.
Hereditary Angiooedema
An autosomal dominant conditon associated with low C1 inhibitors (C1-INH) which results in uncontrolled release of bradykinin leading to oedema. These attacks may be proceeded by painful macular rash leading to painless, non-pruritic swelling of subcut/submucosal tissues. Abdominal pain/vomiting may occur due to visceral oedema.
Management of Hereditary angioedema
C1-INH levels are low during an attack – treat with IV C1-INH concentrate or fresh frozen plasma otherwise. Prophylatic anabolic steroid (Danazol) may help.
Gaucher’s syndrome
A group of autosomal recessive diseases where enzyme dysfunction (glucocerebroside) leads to lipid deposits in organs and cells (moncytes) leading to bruising, fatigue, anaemia, low platelets, liver and splenic enlargement, sclera discolouration and neurological complications.
Retinoblastoma
Most common ocular Ca in kids - presents around 18months. 10% are hereditary - loss of red-reflex and white pupil (can also have strabismus or visual problems). Treat with enucleation, radiotherapy, chemotherapy or photocoagulation.>90% survive into adulthood.
Tuberous Sclerosis
autosomal dominant neurocutaneous condition - ash-leaf spots which fluoresce under UV light, Shagreen patches (roughened patches over the lumbar spine), adenoma sebacem across the nose, subungual fibromata,
Neurologically - developmental delay, epilepsy and intellectual impairment.
Hereditary Sensorineural hearing problems in children
Usher syndrome, Pendred syndrome, Jervell-lange-Nielson syndrome, Wardenburg syndrome
Cleft lip and Palate
1/1000 babies. Polygenic inheritance but risk increased by anti-epileptic use. Failure of fronto-nasal and maxillary or palatine and nasal septum to fuse. 75% will develop normal speech and there is an increased risk of otitis media.
Cleft lip is repaired first (1stwk to 3months) while palates repaired 6-12months.
Downs syndrome: vision and hearing problems
refractive errors are common
20-40% have strabismus
Congenital and acquired cataracts are more common
Recurrent blepharitis
Glaucoma
Otitis media and glue ear are very common resulting in hearing problems.
“Waddling gait”, Gower’s sign, psuedohypertrophy of calves
Duchenne’s muscular dystrophy
What is Alkaptonuria
Can’t process phenylalanine nor tyrosine.
Recessive.
Pee is dark/black.
Damages cartilage and heart valves (>30yrs old).
What is galactosaemia?
Can’t process galactose 1-phosphate. Toxic levels leads to hepatomegaly, renal failure, cataracts, seizure, hypoglycaemia, brain damage etc.
Recessive.
What is maple syrup urine disease (branched chain ketoaciduria)
Recessive.
Hypotonia, seizures, hypoglycaemia, ketoacidosis, opisthotonus, pancreatitis, coma etc
