Chapter 108 Dysmorphology

Question 1

Primary structural defect arising from a localized error in morphogenesis and resulting in the abnormal formation of a tissue or organ is called ______.

Answer 1

Malformation

Question 2

An abnormal organization of cells into tissues is called ______

Answer 2

Dysplasia

Question 3

An alteration in shape or structure or organ that has differentiated normally is called ________.

Answer 3

Deformation

Question 4

A strucutral defect resulting from the destruction of a structure that had formed normally before the insult _______.

Answer 4

Disruption

Question 5

A pattern of multiple abnormalities that are related by pathophysiology and result from a single, defined etiology is called ________

Answer 5

Syndrome

Question 6

The term for multiple malformations that are caused by a single event that can have many etiologies is ________

Answer 6

Sequences

Question 7

The term for nonrandom collection of malformations in which there is an unclear or unknown relationship among the malformations such that they do not fit the criteria for a syndrome is _________

Answer 7

Association

Question 8

DiGeorge sequence of primary fourth branchial arch and 3rd and 4th pharyngeal pouch defects that lead to aplasia or hypoplasia of the thymus and parathyroid glands, aortic arch anomalies, and micrognathia. This is an example of

A. Deformation
B. Disruption
C. Dysplasia
D. Malformation

Answer 8

D

Question 9

Dislocated hips, equinovarous foot deformity, crumpled ears, dislocated nose, small thorax due to oligohydramnios. This is an example of:

A. Deformation
B. Disruption
C. Dysplasia
D. Malformation

Answer 9

A

Question 10

Amnionic membrane rupture leading to amputation of fingers/toes, tissue fibrosis and destructive tissue bands is an example of:

A. Deformation
B. Disruption
C. Dysplasia
D. Malformation

Answer 10

B

Question 11

Neurocutaneous melanosis sequence characterized by poor migration of melanocyte precursor cells from the neural crest to the periphery, manifesting as melanocytic hamartosis of skin meninges is an example of:

A. Deformation
B. Disruption
C. Dysplasia
D. Malformation

Answer 11

C

Question 12

Spondylocostal Dysostosis

Cause/Inheritance pattern:
Clinical features:
Pathogenesis:

Answer 12

Spondylocostal Dysostosis

Cause/Inheritance pattern: Autosomal recessive
Clinical features: Abnormal vertebral segmentation
Pathogenesis: DLL3 mutation (most common)

Question 13

Patient with this syndrome display syndactyly, polydactyly, anteverted nose, ptosis, cryptorchidism, and holoprosencephaly,

Answer 13

Smith-Lemli-Opitz Syndrome (SLOS)

Question 14

SSmith-Lemli-Opitz Syndrome (SLOS) is a result of mutations in which gene?

Answer 14

DCRH7

Question 15

DCRH7 gene is important in the synthesis of ________

Answer 15

cholesterol

Question 16

Many features of SLOS is shared with defects in SHH. Why is this so?

Answer 16

SLOS is caused by mutations in DCRH7 which is important in the synthesis of cholesterol. Cholesterol is important in the posttranslational modification of SHH. Therefore, disturbance in cholesterol cause disturbance in the postranslational modification of SHH, leading to similar defects.

Question 17

Disorder characterized by mental retardation, broad thumbs, toes, hypoplastic maxillae, prominent nose, congenital heart disease.

Answer 17

Rubinstein-Taybi Syndrome

Question 18

Gene mutation associated with Rubinstein-Taybi-Syndrome

Answer 18

CBP mutation

Question 19

Neuronal migration defect that in the males causes a smooth brain with reduction or absence of gyri and sulci and in females gives rise to a variable pattern of mental retardation and seizures.

Answer 19

X-linked lissencephaly

Question 20

Gene mutation associated with X-linked lissencephaly

Answer 20

DCX

Question 21

What is the dosage and timing of folic acid intake for expectant mothers?

Answer 21

400-800 micrograms of folic acid daily 1 month prior to pregnancy.

Question 22

A child with microcephaly, developmental delay, hypeactivity and facial dysmorphic features probably has what syndrome?

Answer 22

Fetal Alcohol Syndrome

Question 23

Two major intrinsic causes of deformations are _______ and ______

Answer 23

Primary neuromuscular disorders and oligohydramnios

Question 24

Three major extrinsic causes of deformations are ________, _________, and ________.

Answer 24

oligohydramnios from chronic leakage of amniotic fluid
breech presentation
abnormal shape of the amniotic cavity

Question 25

T/F most children with deformations from extrinsic causes have poor prognosis

Answer 25

F. most of them are completely normal and their prognosis is usually excellent.

Question 26

A patient with glossoptosis and U-shaped cleft palate most likely has ________

Answer 26

Pierre Robin malformation sequence