Genetics Flashcards
What is the genetic abnormality in Down’s?
Trisomy 21
What are features of down’s?
Learning disability Congenital heart disease Hypothyroidism Immunity problem Early onset alzheimer
What is a congenital anomaly?
Anomaly present at birth - genetic and environmental
What can cause congenital anomalies?
Single gene disorders
Chromosomal disorders
Teratogens
How do we diagnose intellectual disability or malformation syndrome?
History
Description
Recognition of patterns
Testing
What tests can be done for intellectual disability or malformation syndrome?
Microarray
Targetted testing
Moving to exome/genome
How can dysmorphia generally be described?
Position and shape of facial features
Hands
Growth of child
General features
What are features of the head that can be abnormal?
Shape
Size - macro/microcephaly
Ear position - low set, posteriorly rotated indicates lack of maturity
What is low set ears a sign of?
Learning disability - ear goes up with brain while it is growing
What are features of eyes that can be abnormal?
Hypertolerism
Eyes too far apart - midline abnormality
What are features of hands that can be abnormal?
Finger length
Digital abnormalities
Palmar creases
What kind of fingers do marfans patients have?
Arachnodactyly
How is arachnodactyly assessed in marfans?
Middle finger/total hand length ratio >44%
What is syndactyly?
Fused fingers
What can cause polysydactly?
Hox D13
What is Acrocephalopolysyndactyly?
Tall forehead
Polydacyly
Sydactyly
What is pierre robin sequence?
Small chin leads to cleft palatte due to tongue being forced upwards
What is fetal akinesia sequence?
Reduced fetal movement Reduced breathing Contractures Clefting Lung hypoplasia
What is deformation?
Organ is there but abnormal
What is disruption?
Part of organ/body part absent
What is an association?
2+ features that occur together more often than would be expected by chance
What is the VATER association anomaly?
Vertebral anomalies
Ano-rectal atresia
TracheooEsophageal fistula
Radial anomalies
What is the genotype of Turners?
45 X0
What are features of Turner’s syndrome?
Lymphoedema - PUFFY FEET Increased carrying angle Low hairline Wide spaced nipples Short stature occassionaly very mild learning difficulty
What are common congenital problems in Turners?
Coarctation of the aorta
Hypothyroidism
What are features of 22q11 deletion?
Cleft palate Abnormal facies Thymic hypolplasia - immune deficiency Calcium Heart problems
What are facial features of 22q11 deletion?
Low set eyelids
Almond shape eyes
Crumpled ear
Long nose
