Genetics Flashcards
Presentation of Down syndrome
LD CHD hypothyroidism immunity Early onset Alzheimer disease
Genetics of down syndrome
Trisomy 21
What to look at in the examination of a dysmorphic child
position and shape of facial features
Hands
Growth of child
general features
What does low set posteriorly rotated ears indicate?
Lack of maturity
Types of sizes of head
macroencephaly
Microencephaly
What is orbital hypertelorism?
Increased distance between eyes
- inner canthal distance ICD and inter pupillary distance IPD increased
What to look at at the eyes to look at a dysmorphic child
Hypertelorism
Telecanthus / epicanthic folds
- ICP and IPD increased
What hand measurements are done?
Finger length
Digital abnormalities
Palmar creases
Examples of conditions where hand measurements would be altered
Marfan syndrome
Down syndrome
How can malformation present?
Alone
As part of a syndrome
Features of acrocephalopolysyndactyly
Tall forehead
Polydactyly
Syndactyly
Pierre-Robin sequence
Small chin to cleft palate
Fetal akinesia sequence
Reduced foetal movement reduced breathing contractures clefting lung hypoplasia Abnormal limp position
What is deformation and disruption?
Pattern of development normal to start with but becomes abnormal
Derformation vs disruption
Deformation = Organ parts are there Disruption = parts of organ / body parts absent
What is association?
Two features or more occur together often than expected than by chance
VATER of association stands for…
Vertebral anomalies
Ano rectal atresia
Tracheo oesophageal fistula
Radial anomalies
Genetics of turners syndrome
45, X
Presentation of turner syndrome
Lymphodema - puffy feet - nuchal translucency - cystic hygroma Increased carrying angle low hairline wide sp nipples sandal gap short stature Very mild LD Coarctation of aorta Hypothyroidism UTI Osteoporosis HTN Primary amenorrhea and infertility
Genetic investigations of LD
Microarray
Fragile X
Targeted tests driven by phenotype
Presentation of 22q11 deletion syndrome
Cleft palate Abnormal facies thymic hypoplasia/immune deficiency calcium heart problems - caused by 22 deletion - "catch 22"
What is Glut 1 deficiency caused by?
SLC2A1 deletion or mutation
Treatment of glut 1 deficiency
Ketogenic diet
Feature of her occiput in downs syndrome?
Flat occiput
CF is caused by a mutation on which chromosome?
Chromosome 7
Inheritance of Prader willi syndrome
Imprinting
Describe imprinting
The patient does not have to receive gene from father
The mothers gene may be normal but that does not prevent the phenotype from occurring.
What does the phenotype of PW syndrome consist of?
Obesity
LDs`
Hypotonia
Desire to eat
What diet should CF patients have?
High calorie and high fat
With pancreatic enzyme supplementation for every meal
What is genetic application?
Hereditary diseases have an earlier age of onset through successive generations
Examples of diseases with genetic application
Huntingtons
Myotonic dystrophy
What is fragile X associated with?
Mitral valve pr olapse
Features of fragile X
LDs
Macrocephaly
Large ears
Macro-orchidism
