Lecture 5: Dysmorphology, Anomalies, and Teratogens Flashcards
Birth Defect (Dysmorphic Feature)
A condition present at birth which requires medical, surgical, or cosmetic intervention.
About 3% of children at birth, 4% by one year.
i.e. Congenital heart disease, neural tube defect, polydactyly.
Poor formation of tissue.
Malformation.
i.e. cleft lip
Unusual forces on normal tissue.
Deformation.
i.e. clubbed feet
Breakdown of normal tissue.
Disruption.
i.e.
Abnormal organization of cells in tissue.
Dysplasia.
i.e. osteogenesis imperfecta
Syndrome
A recognizable pattern of multiple recurrent anomalies that are pathogenetically related.
i.e. Progeria, Down Syndrome
Association
A pattern of anomalies that occur 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 closure of the soft palate, resulting in a cleft palate.
Potter Sequence
In utero, lack of fetal urination (secondary to non-functional kidneys or urine outlet) leads to anhydramnios, which leads to fetal compression and pulmonary hypoplasia and ultimately, death.
What is a teratogen?
Substances encountered during pregnancy which can lead to birth defects.
What are the sources of teratogens?
- Infectious (Rubella, Syphillis)
- Medications (Thalidomide, Accutane)
- Drugs of Abuse (Cocaine, Alcohol
- External Agents (Radiation, Hyperthermia)
- Maternal Disorders (Lupus, Diabetes)
Contrast syndromes, sequences, and associations.
- Syndrome is due to a genetic factor.
- Sequence is due to a mechanical factor.
- Association is due to an unknown factor.
What is classified under metabolic disorders?
Disorders that have to do with
- Lipid storage
- Peroxisomal
- Golgi
- Mitochondrial
- Urea Cycle
- Carbohydrate Metabolism
