Dysmorphology-Lecture 9/2/21 Flashcards
Dysmorphology
Study of the abnormal form
Microcephalic
Abnormally small head around the forehead
Macrocephaly
Abnormally big head
Docelocephaly
Abnormally long head
Bachiocephaly
Flat face
Phagiocephaly
Flat side of the head, maybe from laying on one side
Hair dysmorphias
Double hair whorl, low posterior hair line, High/low anterior hair line
Bitemporal narrowing
Narrow forehead
Frontal bossing
Bilateral bulging of the lateral aspects of the forehead
Micrognathia
Small chin
Retrognathia
Chin behind the plane of the face
Periorbital region
Should be evenly spaced between palpebral fissure length and inner canthal length
Palpebral fissure
When the eye is open, outside formed by eyelid margins
Telecanthus
Increases distance between medial canthi
Hypertelorism
Increased inter-pupillary distance
Slant of palpebral fissures
Can be upslant or downslant, angle formed by a line
Microcia
Small or malformed ears that can lead to hearing loss if no canal
Low set ears
Set below the line between canthi and occipital protuberance
Philtrum
The space between the moth and nose
Bifid uvula
More than one uvula
Clinodactyly
A digit that is laterally curved in the plane of the palm
Syndactyly
A soft tissue continuity on the A/P axis between two fingers that extends dismally
Why look for minor anomalies?
The more minor anomalies you find, the more likely a major anomaly is present
Malformation
Poor formation of the tissue (etc cleft lip, spina bifida). More likely to have a genetic component
Deformation
Unusual forces on normal tissue ex (club foot, potter’s facies, overlapping toes)
Disruption
Breakdown of normal tissue due to environmental disturbance ex (oligodactyly amniotic bands, intestinal atresia, cleft palate)
Dysplasia
Abnormal organization of cells into tissues ex: poly cystic kidney disease, arachnodactyly, pectins excavating, skeletal dysplasia
Sequence
Cascade effects from single known anomaly or mechanical factor
Ex mandibuar hypoplasia leads to posterior displacement tongue, leads to posterior U shaped cleft palate
Syndrome
Multiple anomalies stemming from one pathogenic source (ex: MArfans)
Association
Non-random occurrence of multiple anomalies that cannot be explained by chance that has no known genetic cause
Teratogens
An exposure during a pregnancy that has a harmful fetal effect
Congenital Cytomegalovirus
Often asymptomatic mother in pregnancy, causes macrocephaly, intracranial calcifications, sensorineural hearing loss, rash, low birth weight
Teratogens to know (6)
CMV (cytomegalovirus) Rubella Thalidomide Fetal alcohol syndrome Warfarin Acutane
Teratogen types (7)
- Infection
- Mediations
- Drugs of abuse
- Heavy metals
- External agents
- Maternal conditions
- Procedures
Thalidomide exposure
Anti-nausea given in the 50s and leads to malformed limbs
Fetal alcohol syndrome
Macrocephaly, Smooth philtrum, thin upper lip, micrognathia, palpebral fissures, minor ear abnormalities, low IQ
Acutane
35% have major malformations including conotruncal heart defects, cranial nerve palsies, absence of cerebellum vermis, moderate to severe ID
25% with no malformations have ID
Major Anomalies
Anomalies that affect function (cleft lip/palate, congenital heart disease, neural tube defects, omphalocele, microcia etc)
Minor anomalies
Generally cosmetic, more minor anomalies increases chance of major (Epicanthal folds, hypo-hypertelorism, Palpebral shape/slant, flat or prominent occipital, Frontal bossing, etc)
Association
Non-random occupancy of multiple anomalies that cannot be explained by chance, no identified genetic cause
VACTERL
Vertebral anomalies, cardiac anomalies, tracheoesophageal anomalies, esophageal atresia, renal anomalies, radial dysplasia, limb anomalies
