CLASSIFICATION OF ANOMALIES OF DEVELOPMENT OF HUMAN BODY

Presentation by

Al auf Jalaludeen

1

There are four broad categories in theclassification of developmental defects.Anomalies result from either the abnormaldevelopment of a tissue or structure or thesecondary deformation or disruption of anormal structure.

2

Categories of anomalies

Malformation

Deformation

Disruption

Displasia3

Malformation

Malformations occur during formation ofstructures. They may result in complete orpartial absence of a structure or in alterations ofits normal configuration. Most malformationshave their origin during the 3rd to 8th week ofgestation.

4

Malformations are caused by :

Chromosomal abnormality

Genetic disorder

Teratogenic causes

5

Chromosomal abnormality

A chromosome anomaly, abnormality, aberration, ormutation is a missing, extra, or irregular portion ofchromosomal DNA. It can be from an atypical number ofchromosomes or a structural abnormality in one or morechromosomes.

Structural abnormalities can take several forms:

Deletions, duplications, translocations, inversions,insertions, rings and isochromosomes.

6

7

8

Genetic disorder

A genetic disorder is an illness caused by one ormore abnormalities in the genome, especially acondition that is present from birth(congenital). Most genetic disorders are quietrare and affect one person in every severalthousands or millions.

9

10

Teratogenic causes

Teratogenic exposure during prenatal developmentcause disruptions regardless of the developmentalstage or site of action. Most structural defects causedby teratogenic exposures occur during theembryonic period, which is when criticaldevelopmental events are taking place and thefoundations of organ systems are being established.

11

Various teratogenic sources:

Radiation

Infectious agents

Thermodisruptions

Toxic metals

Chemical exposures

Maternal conditions

Smoking and certain drugs

Assisted reproductive technologies12

13

14

Deformation

Deformations result from mechanical forces that mold apart of the fetus over a prolonged period. It often involvethe musculoskeletal system and may be reversible postnatally.

Deformations are caused by:

Extrinsic factors (fetal constraint)

Intrinsic factors (fetal akinesia)15

Extrinsic factors

Infants with IUGR (intrauterine growth restriction) canexhibit early symmetric or late asymmetric growthabnormality patters depending on the fetal stage ofdevelopment. Deformation is the consequence of extrinsicbiomechanical factors interfering with the normal growth,functioning or positioning of the fetus in the uterus,typically arising during late gestation.

16

17

Intrinsic factors

Fetal akinesia deformation sequence is a clinically andgenetically heterogeneous disorder characterized by avariable combination of arthrogryposis, fetal akinesia,intrauterine growth restriction, developmentalabnormalities such as cystic hygroma, pulmonaryhypoplasia, cleft palate, cryptorchidism, cardiac defects,intestinal malrotation and occasional pterygia of the limbs.

18

19

Disruption

Disruptions result in morphological alterations of already formed structures and are caused by destructive processes.

Disruptions occur by:

Vascular

Compression

Tearing

20

Dysplasia

Dysplasia is an ambiguous term used in pathology to refer to anabnormality of development or an epithelial anomaly of growth anddifferentiation.

Dysplasia is characterized by four major pathological microscopic changes:

Anisocytosis (cells of unequal size)

Poikilocytosis (abnormally shaped cells)

Hyperchromatism (excessive pigmentation)

Presence of mitotic figures (an unusual number of cells which are currentlydividing)

21

22

23