selected syndromes

Question 1

syndrome def

Answer 1

The aggregate of signs & symptoms
associated with any morbid process,
& constituting together the picture
of the disease

Question 2

Cytogenetic Disorders

Answer 2

• Alteration in chromosome #
– Euploidy, aneuploidy
• 45, X (Turner’s syndrome)
• 47, XXY (Klinefelter’s syndrome)
• Alteration in chromosome structure (1 or
more)
– Translocation
– Deletion
– Inversion
– Ring chromosomes

Question 3

• Proband

Answer 3

– The individual who initially presents w/ an
identifiable disorder prompting the genetic
study

Question 4

• Penetrance

Answer 4

– The frequency w/ which an inheritable
trait is manifested by individuals carrying
the gene for that trait (%)

Question 5

expressivity

Answer 5

– The extent or degree to which the
inheritable traits are manifested by the
individual

Question 6

Modes of Genetic Transmission

Answer 6

• Autosomal dominant (most common)
• Autosomal recessive (sickle-cell dz)
• X-linked dominant (vit D resistant
rickets)
• X-linked recessive (hemophilia A)
• Y-linked

Question 7

TRISOMY 21

Answer 7

• Aka Down syndrome
• Most common/best known of the
malformation syndromes
• 1/650 live births
• Association with increased maternal
age
– 38/1000 live births at 44 years of age or
older

Question 8

clinical features of trisomy 21

Answer 8

• Upslanting lateral palpebral fissures
• Low nasal bridge
• Mental retardation
• Broad, wide neck
• Simian crease (palm: single palmar crease)
• Small, malformed ears

Question 9

oral features of trisomy 21

Answer 9

– Relative macroglossia, fissured tongue
– Delayed tooth eruption, hypodontia
– Narrow palate, malocclusion
– Taurodontism

Question 10

Treacher Collins Syndrome

Answer 10

•Defects from first and second
branchial arches
•Autosomal dominant/sporadic (60%
new mutations); 1 in 25,000-50,000
live births; associated with increased
paternal age
•Gene mutation (treacle or TCOF1)
mapped to chromosome 5q32-q33.
•Variable expressivity; severity
increases with successive generations

Question 11

clinical features of teacher collins

Answer 11

– Hypoplastic zygomas; coloboma (notch in
outer lower eyelid)
– Ear anomalies: deformed/misplaced
pinnae, extra ear tage, conductive
hearing loss due to absence of external
auditory canal
– Retruded, small mandible; condylar
hypoplasia
– 15% patients have lateral facial clefts;
macrostomia
– Cleft palate in 1/3 of patients
– Hypoplastic/absent parotids
– Respiratory complications
– NO intellectual impairment

Question 12

crouton syndrom ceph appearance

Answer 12

beaten copper

Question 13

difference between apart and crouzon

Answer 13

syndactyly of the hands

Question 14

The presence of multiple odontogenic
keratocysts in the same patient is strongly
suggestive of this syndrome!

Answer 14

Nevoid Basal Cell
Carcinoma Syndrome
(Gorlin Syndrome)

Question 15

features of goblin syndrome

Answer 15

palmar and plantar pits
spina bifida
falx cerebri calcification

Question 16

gardner syndrome

Answer 16

• Aka Familial Adenomatous Polyposis
(FAP)
• Autosomal dominant, near 100%
penetrance
• 1/3 cases are spontaneous mutations
• Mutation mapped to the APC gene
(adenomatous polyposis coli gene) on
chromosome 5
• 1:8,300 to 1:16,000 live births
colon polyps

Question 17

skeletal manifestations of gardner syndrome

Answer 17

• Skeletal anomalies in 90% of patients
– Osteomas most common
• Commonly skull, paranasal sinuses, mandible
• Usually noted during puberty, before onset of
bowel symptoms
• Usually have 3-6 osteomas

Question 18

dental abnormalities of gardner syndrome

Answer 18

• Dental abnormalities
– Odontomas
– Supernumerary teeth
– Impacted teeth

Question 19

McCune-Albright Syndrome

Polyostotic Fibrous Dysplasia

Answer 19

• Genetics
– Sporadic postzygotic mutation GNAS 1 gene
• Clinical
– Tumor-like condition in which normal bone is
replaced by cellular fibrous connective tissue
with irregular bony trabeculae
– Jaw & skull can be affected, though polyostotic
fibrous dysplasia more frequently involves the
long bones

Question 20

Jaffe-Lichtenstein syndrome

Answer 20

PFD + café au

lait pigmentation

Question 21

McCune-Albright syndrome

Answer 21

PFD + café au
lait pigmentation + multiple endocrinopathies
– Sexual precocity, pituitary adenoma, or
hyperthyroidism

Question 22

radiographic appearance of mccue alb rights

Answer 22

“ground glass” or

“orange peel” appearance

Question 23

Sjögren Syndrome

Answer 23

• Autoimmune disorder
• Salivary & lacrimal glands involved
• Classification
– Primary
• Sicca syndrome alone (xerostomia +
xerophthalmia)
– Secondary
• Sicca syndrome + another autoimmune disease