Chapter 10 - Diseases of Infancy and Childhood

Question 1

Most common cause of death in
Neonate (first 4 weeks)
Infants (up to 1 year old)
1-4 years old
5-14 years old

Answer 1

Neonate & infants:
Top 1: Congenital Anomalies
Top 2: Prematurity

1-14 years old:
Accidents/unintentional injuries

Question 2

Defects in these organs usually become clinically apparent years later

Answer 2

Cardiac and renal defects

Question 3

Primary errors of morphogenesis in which there is an INTRINSICALLY ABNORMAL DEVELOPMENTAL PROCESS

Answer 3

Malformations

Question 4

These result from secondary destruction of an organ or body region that was previously normal in development;
arise from EXTRINSIC DISTURBANCE IN MORPHOGENESIS

Answer 4

Disruptions

Question 5

Most common example of disruption

Answer 5

Amniotic bands

Question 6

Represent an extrinsic disturbance of development due to ABNORMAL BIOMECHANICAL FORCES

Answer 6

Deformations

Question 7

Most common underlying factor for deformations

Answer 7

Uterine constraint

Usually in 35-38 weeks of gestation:
Fetal development occurs faster than uterine growth
Decrease in amniotic fluid (serves as cushion)

Question 8

Factors leading to Uterine constraint

Answer 8

MATERNAL FACTORS
first pregnancy
small uterus
bicornuate uterus
leiomyomas

FETAL FACTORS
oligohydramnios (Potter sequence)
multiple fetuses
abnormal fetal presentation

Question 9

A cascade of anomalies triggered by one irritating aberration

Answer 9

Sequence

Question 10

Potter sequence

Answer 10

Causes of oligohydramnios:
amniotic fluid leakage
uteroplacental insufficiency (due to maternal hypertension or severe toxemia)
renal agenesis

Classic phenotype of Potter sequence:

(1) flattened facies
(2) positional abnormalities of limbs (talipes equinovarus of clubfoot)
(3) hip dislocation
(4) hypolastic lungs
(5) amnion nodosum

Question 11

Constellation of congenital anomalies believed to be pathologically related, but cannot be explained by a single, localized initiating event

Answer 11

Malformation syndrome

50% of malformations are isolated; 50% are part of a syndrome

Question 12

Refers to the complete absence of an organ AND its associated primordium

Answer 12

Agenesis

Question 13

Refers to the absence of an organ but due to failure of growth of an existing primordium

Answer 13

Aplasia

Question 14

Described as the absence of an opening usually of a hollow visceral organ

Answer 14

Atresia

Question 15

Refers to incomplete development or decreased size of an organ with decreased number of cells

Answer 15

Hypoplasia

Question 16

Most common cause of anomalies

Answer 16

Unknown (1/2 to 3/4 of the total cases)

Question 17

Caused of anomalies

Answer 17

Genetic
Environmental
Multifactorial

Question 18

Most common known cause of anomalies

Answer 18

Multifactorial

Question 19

Most common cause of genetic anomalies

Answer 19

Chromosomal anomalies

Virtually all chromosomal syndromes are associated with congenital malformations

Question 20

Most common developmental defect of the forebrain and midface

Answer 20

Holoprosencephaly

Question 21

Signaling pathway that is critically affected in holoprosencephaly

Answer 21

Hedgehog signaling pathway

Question 22

Most common cause of viral infection-related anomalies

Answer 22

Rubella

Question 23

Most common causes of drug-related anomalies

Answer 23

thalidomide (phocomelia)
alcohol (fetal alcohol syndrome)
anticonvulsants (like valproic acid)
warfarin
13-cis-retinoic acid