Dysmorphology Flashcards
Malformation v Deformation
whats the difference
Malformation
- a clinically significant abnormality in form or function that results from localizard, intrinsitic defects in morphogenesis, occuring in embryonic or early fetal life
examples
- cleft lip/pallet
- tetrology of fallot
- usually traced back to a gene defect & require surgical repair
- multiple malformations appearing together: can be part of a malformation sequence, syndrome or association
Deformation
- something that arises from the environment forces acting on the tissue
- example: a fetus growing in a uterus with a fibroid: the fetus will not be able to move limbs : decreased ROM and contractures will result
examples
- club foot
- arthropgryposis multiplex congentia
Syndromes
arise from what
Clinical genetic syndromes can occur from….
- single gene mutation
- chromosomal abnormality
- exposure to teratogenic agent
- unknown factors
Approach to a Child with Facial Abnormalities
History
- birth weight (SGA, LGA, AGA)
- small BW: think teratogen expsoure and chromosomal
- large BW: maternal DM, BW syndrome
- premature or full term baby ; postmatrue = trisomy
- vaginal v. C section
- parental age at time of delivery
- moms: hx., meds, alcohol, drugs during preg.
- delayed quickening (fist feeling) = hypotonia
- amoutn of aminotic fluid: inc. = obstruction, CNS issue
- decreased = renal/urinary issue
3 generations of family hisotry to get good idea about genetic or familial influence
- simialr seen in 1st and 2nd degree relatives
- history of otehrs with neonatal loss or gentic syndromes
Physical Exam: looking for other abnormalities which may point to a syndrome
- height, weight & head circumference
- small size: chromosomal, skletal or teratogenic
- large: overgrowth, maternal DM
- Limbs: Proportional to head & trunk? short v long etc.
- head shape
Target appraoch to proper lab testing
Physical Exam Finding for dysmorphologies: Head Shapes
Head Shapes
- in newborns: molding can cause weird shapes: resovles within a few days
Shapes To Note 1 week post birth
Normocephaly
Dolichocephaly/scaphocephaly = long & thin head
- long and narrow front to back
Brachycephaly = norrow in the AP diamter and broad laterally
- tall and skinny
Plagiocephaly = asymmertric in shape
Physical Exam: Facial Features
how to approach looking at the face
asymmetric due to?
Facial Features PE
asymmetric: due to deformation > malformation (something in utero was pushing against 1 side of face)
Divide face into 4 quadrant
1. forehead
2. midface: eyebrows to upper lip (includes eyes)
3. malar region: the upper ear to midface
4. mandible: extends from lower ear to lower ear & has lower lip
Physical Exam: Facial Features
Forehead evaulation
Prominent
Frontal Bossing
Sloping
Forehead Shapes on PE
- can be prominent = like in achrondroplasis (dwarfism)
- can be deficient, sloping in those withi microcephaly
Prominent Forehead
- bluding out the front
Frontal Bossing
- larger than normal frontal bone: flat on teh front creating a prominet brow bone line & spares the midline
Sloping Forehead
- starts tiny and comes out (downward sloping)
Physical Exam: Facial Features
Midface Features
what are you looking at
Midface Features
- hypoplasia of the midface (via measurements) can show many syndromes (DS, FAS)
Eyes: To Note
- distance between eyes (hypo/hypertelorism: should be 1 eye distance between)
- interpupillary distance
- length of palpebral fissures
- dirction of palperbral fissure
- upward slant : down syndrome
- downward slant: Tracher Collins or Noonan syndrome
- epicanthal folds (the skin fold in the inner eye corner): downs syndrome, fetal alcohol
Nose : To Note
- flattening of the nasal bridge: down syndrome and fetal alcohol syndrome
- depressed nasal bridge (inward): dwarfism
Physical Exam: Facial Features
Midface: assess ears and distance to the eye
Midface: Ear to Eye Distance
- malar region: assess the position and angle of teh ears
- can be low set ears due to malformations or an issue with the mandibular region
- draw line from the edge of the eyes to the top of the ears
- there should be approx. 1/3 of the ear above the line drawn from the corner of the eye
Physical Exam: Facial Features
Mouth/Lips Region
Mandibular Region
Mouth/Lips
- philtrum: smooth = featl alcohol syndrome
- cleft lip/palate
- arched palate
- size of tongue (marcoglossia: down syndrome)
Mandibular Rregion
- mandible = small: micrognathia (trisopy 13, fetal alcohol, progeria)
- mandible = large: prognathia (acuired syndrome = not congeital)
Physical Exam: Facial Features
Neck Features
Webbing
- turner syndrome
- noonan syndrome
Shortening of neck
- skeletal dysplasias
- abnormal cervical spine
Posterior Hairline
- Turners syndrome
- genetic syndromes (others)
Physical Exam: Chest Features
sheilf shpae
pectus abnormbs.
chest asymmetry
Sheild Shape
- noonan syndrome
- turners syndrome
Pectus Abnormalities
- excavatum (inward)
- carinatum (outward)
- think marfans
Chest Asymmetry
- poland sequence
Physical Exam: Extremities Features
- general appraoch
- hands and feet findings
Exam
- always assess every ROM
- extremities are invovled in lots of syndromes
- joint contracture: think neuromusk. issue
- inability to pronante/supanate (radioulnar synostosis) = FAS and some X linked disorders
HAnds and Feet
- polydactyly (+) can be isolated OR trisomy 13
- oligosactyly (-) for fanconi syndrome or amniotic band distruption
- syndactatyly = fused together
Palmar Crease
- transverse palmar crease: indicates low tone in fetal life & seen in down syndrome
- “hockey stick apperance”
Sandal Gap Appearance
- windened between first and second toe
- down syndrome
Physical Exam: Genitalia
- exam for abnormalities in structure
Males: measure penis ( micropenis = < 1.9 cm)
ambiguous genitalia: think endocrine or chromosome disorders
hypospadias (urethra in the back)
Diagnostic Evaulation of dysmorphologys
what tests are done
Crhomosomal microarry analysis (CMA) for
- multiple congenital abnormalities
- invovling 1+ major organ systems or 2+ dysmorphic features
- intellectual disability
- ASD
Karyotyping
FISh testing: when specific disorders are tested
Imaging as needed
Acrondroplasia
Etiology
Clinical Features
Etiology
- most common short-limbed dwarfism
- autosomal dominant trait BUT 80% are due to a mutation in the fibroblast growth factor gene (FGFR3)
- disorder of cartilage calcificaltion and remodeling
Genetics
- heterozygotes = normal fertibiltiy, life and intelligence
- homozygotes: stillborn, pulmonary complications & brainstrem conpression
Clinical Features
- short stature with disproportinately short limbs compared to the trunk
- promximal segments affected more than distal
- long bones shortened and bowed
- small digits
- excessive lumbardosis and kyphoscoliosis
- large head: frontal bossing and depressed nasal bridge
- high risk for hydrocephalus because small formane magnus and increase ICP, need fot a VP shunt
Treatment
- limbg lengthening surgery is an option but controversial
- surgical management of the bowing long bones and the kyphoscoliosis
- VP shutn for hydroceph.
