Chapter 108 Dysmorphology Flashcards
Primary structural defect arising from a localized error in morphogenesis and resulting in the abnormal formation of a tissue or organ is called ______.
Malformation
An abnormal organization of cells into tissues is called ______
Dysplasia
An alteration in shape or structure or organ that has differentiated normally is called ________.
Deformation
A strucutral defect resulting from the destruction of a structure that had formed normally before the insult _______.
Disruption
A pattern of multiple abnormalities that are related by pathophysiology and result from a single, defined etiology is called ________
Syndrome
The term for multiple malformations that are caused by a single event that can have many etiologies is ________
Sequences
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 _________
Association
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
D
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
A
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
B
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
C
Spondylocostal Dysostosis
Cause/Inheritance pattern:
Clinical features:
Pathogenesis:
Spondylocostal Dysostosis
Cause/Inheritance pattern: Autosomal recessive
Clinical features: Abnormal vertebral segmentation
Pathogenesis: DLL3 mutation (most common)
Patient with this syndrome display syndactyly, polydactyly, anteverted nose, ptosis, cryptorchidism, and holoprosencephaly,
Smith-Lemli-Opitz Syndrome (SLOS)
SSmith-Lemli-Opitz Syndrome (SLOS) is a result of mutations in which gene?
DCRH7
DCRH7 gene is important in the synthesis of ________
cholesterol
Many features of SLOS is shared with defects in SHH. Why is this so?
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.
Disorder characterized by mental retardation, broad thumbs, toes, hypoplastic maxillae, prominent nose, congenital heart disease.
Rubinstein-Taybi Syndrome
Gene mutation associated with Rubinstein-Taybi-Syndrome
CBP mutation
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.
X-linked lissencephaly
Gene mutation associated with X-linked lissencephaly
DCX
What is the dosage and timing of folic acid intake for expectant mothers?
400-800 micrograms of folic acid daily 1 month prior to pregnancy.
A child with microcephaly, developmental delay, hypeactivity and facial dysmorphic features probably has what syndrome?
Fetal Alcohol Syndrome
Two major intrinsic causes of deformations are _______ and ______
Primary neuromuscular disorders and oligohydramnios
Three major extrinsic causes of deformations are ________, _________, and ________.
oligohydramnios from chronic leakage of amniotic fluid
breech presentation
abnormal shape of the amniotic cavity
T/F most children with deformations from extrinsic causes have poor prognosis
F. most of them are completely normal and their prognosis is usually excellent.
A patient with glossoptosis and U-shaped cleft palate most likely has ________
Pierre Robin malformation sequence
