Dysmorphology, anomalies and teratogens Flashcards
clinical geneticists
interpret genetic information and give diagnoses
-involved in diagnosis, councelling, and care of individuals and families
what circumstances to consult a geneticist
- prenatal testing abnormalities
- birth defects
- child or adult with unusual appearance
- family history of genetic disorders
- infertility or recurrent miscarriage
- early onset of cancer/ fam history
why diagnose
-defines problem
-prognosis
-explains why this happened
-genetic counselling of family
recurrence risk
birth defect
condition present at birth which requires medical, surgical, or cosmetic intervention
-3% of children at birth, 4% by age 1 (some are hard to see)
concurrence of major and minor anomalies
the more minor anomalies you have, the more likely it is to have a major one causing them
what constitutes a clinical dysmorphology
- found in small population
- features occur more commonly in genetic syndromes
- three or more dysmorphologies
making a diagnosis
history physical exam -prenatal/postnatal -association/sequence lab/radiology
history
postnatal: development and behavior, medical-organ systems
- family: developomental delay, birth defects, genetic conditions, ethnic background, consanguinity
- prenatal: prior obstetric history, patients pregnancy info
- perinatal: labor and delivery, hospital course, home course
physical exam
weight/growth curves
- eye positioning
- ear heigth/angle
malformation
- the baby was born with a defect
- cleft lip
deformation
baby was born/grew normally but then somewhere in life there was a physical force (traumatic event) that changed the physical characteristics of that person
-club foot
disruption
born normal and there wsa some kind of biological disruption that happened along the way, leading to a physical change
-amniotic band syndrome
dysplasia
abnormal cellular organization or function in certain tissue types leading to clinically apparent structural changes
syndrome
a recognizable pattern of reccurent multiple anomalies
- downs
- progeria
association
a pattern of anomalies that happen together frequently, without a known, underlying cause
sequence
a pattern of multiple anomalies derived from a single known or presumed prior anomaly or mechanical factor
pierre robin sequence
in utero, the chin is very small and the tongue prevents clocure of the soft palate
-after birth the small chin causes the tongue to fall back and obstruct the airway
potter syndrome
- in utero, lack of fetal urination caused by absent or nonfunctional kidneys or blockage of urine outlet
- leads to anhydramnios which leads to fetal compression and pulmonary hypoplasia resulting in neonatal death
etiology of intellectual disability
- multiple congenital malformations
- metabolic
- isolated intellectual disability
- cerebral palsy/seizures
- central nervouse system lesion
- environmental
teratogens
- substances encountered during pregnancy that could lead to birth defects
- could be: infectious, medications, drugs, external agents (radiation), maternal disorders
- effect on the fetus is highly dependant on the gestational age at time of exposure and dose
fetal alcohol syndrome characteristics
- epicanthal folds
- small eye openings
- flat midface
- upturned nose
- smooth philtrum
- thin upper lip
most birth defects are from
unknown causes
originating factors of :
- syndromes
- sequences
- association
syndrome: gentic
sequence: mechanical factor
association: unknown
