This document discusses the classification of anomalies of human development. There are four broad categories: malformations, deformations, disruptions, and dysplasias. Malformations occur during structure formation and may involve absence or alterations of structures. They are caused by chromosomal abnormalities, genetic disorders, or teratogenic exposures during development. Deformations result from mechanical forces that mold tissues over time and often involve the musculoskeletal system. Disruptions alter already formed structures through destructive processes like vascular issues, compression, or tearing. Dysplasias refer to abnormalities in development or growth of epithelial tissues.

1. CLASSIFICATION OF ANOMALIES OF
DEVELOPMENT OF HUMAN BODY
Presentation by
Al auf Jalaludeen
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2. There are four broad categories in the
classification of developmental defects.
Anomalies result from either the abnormal
development of a tissue or structure or the
secondary deformation or disruption of a
normal structure.
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3. Categories of anomalies
 Malformation
 Deformation
 Disruption
 Displasia
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4. Malformation
Malformations occur during formation of
structures. They may result in complete or
partial absence of a structure or in alterations of
its normal configuration. Most malformations
have their origin during the 3rd to 8th week of
gestation.
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5. Malformations are caused by :
Chromosomal abnormality
Genetic disorder
Teratogenic causes
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6. Chromosomal abnormality
A chromosome anomaly, abnormality, aberration, or
mutation is a missing, extra, or irregular portion of
chromosomal DNA. It can be from an atypical number of
chromosomes or a structural abnormality in one or more
chromosomes.
Structural abnormalities can take several forms:
Deletions, duplications, translocations, inversions,
insertions, rings and isochromosomes. 6

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9. Genetic disorder
A genetic disorder is an illness caused by one or
more abnormalities in the genome, especially a
condition that is present from birth
(congenital). Most genetic disorders are quiet
rare and affect one person in every several
thousands or millions.
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11. Teratogenic causes
Teratogenic exposure during prenatal development
cause disruptions regardless of the developmental
stage or site of action. Most structural defects caused
by teratogenic exposures occur during the
embryonic period, which is when critical
developmental events are taking place and the
foundations of organ systems are being established.
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12. Various teratogenic sources:
 Radiation
 Infectious agents
 Thermodisruptions
 Toxic metals
 Chemical exposures
Maternal conditions
 Smoking and certain drugs
 Assisted reproductive technologies
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15. Deformation
Deformations result from mechanical forces that mold a
part of the fetus over a prolonged period. It often involve
the musculoskeletal system and may be reversible post
natally.
Deformations are caused by:
Extrinsic factors (fetal constraint)
Intrinsic factors (fetal akinesia)
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16. Extrinsic factors
Infants with IUGR (intrauterine growth restriction) can
exhibit early symmetric or late asymmetric growth
abnormality patters depending on the fetal stage of
development. Deformation is the consequence of extrinsic
biomechanical factors interfering with the normal growth,
functioning or positioning of the fetus in the uterus,
typically arising during late gestation.
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18. Intrinsic factors
Fetal akinesia deformation sequence is a clinically and
genetically heterogeneous disorder characterized by a
variable combination of arthrogryposis, fetal akinesia,
intrauterine growth restriction, developmental
abnormalities such as cystic hygroma, pulmonary
hypoplasia, cleft palate, cryptorchidism, cardiac defects,
intestinal malrotation and occasional pterygia of the limbs.
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20. Disruption
Disruptions result in morphological alterations of already
formed structures and are caused by destructive processes.
Disruptions occur by:
Vascular
Compression
Tearing
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21. Dysplasia
 Dysplasia is an ambiguous term used in pathology to refer to an
abnormality of development or an epithelial anomaly of growth and
differentiation.
 Dysplasia is characterized by fourmajor pathologicalmicroscopic changes:
 Anisocytosis (cells of unequal size)
 Poikilocytosis (abnormally shaped cells)
 Hyperchromatism(excessive pigmentation)
 Presence of mitotic figures (an unusual number of cells which are currently
dividing) 21

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