Dysmorphism
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Dysmorphism refers to abnormalities in morphological development where structures can appear in different forms. Dysmorphism can be facial or structural and is seen in dysmorphic features which are differences in body structure that can be isolated or related to genetic disorders. Common dysmorphic features include variations in eye spacing, philtrum length, and nose shape. The causes of dysmorphism include chromosomal abnormalities, single gene mutations, teratogen exposure, and environmental factors during development.
Dysmorphism
- 1. Dysmorphism 1. an abnormality in morphologic development.dysmorphic 2. allomorphism. 3. ability to appear in different morphological forms.
- 2. What is Dysmorphism? • Also called dysmorphia which in Greek means badness of form; this refers to the malformations or an abnormality in the shape and size of the body. • Dysmorphism can be facial or structural
- 4. What is body dysmorphic disorder or feature? • A dysmorphic feature is a difference of body structure. It can be an isolated finding in an otherwise normal individual, or it can be related to a congenital disorder, genetic syndrome, or birth defect. • Dysmorphic features can vary from isolated, mild anomalies such as clinodactyly or synophrys to severe congenital anomalies such as heart defects and holoprosencephaly
- 5. Common Dysmorphic features Wide spacing , between eyes, hypertelorism, Narrow spacing , between eyes, hypotelorism, Palpebral , fissure length, Epicanthal folds.
- 6. Common Dysmorphic Features Philtrum length „ Upper lip „ Shape of nose
- 7. Cause of Syndromes • • • • „ „ „ „ Chromosomal aneuploidy Single Gene abnormalities Teratogen exposure Environmental
- 8. Teratogens and Dysmorphology • • • • • • • Medications or drugs the developing fetus is exposed to can result in a number of birth defects. „ The timing of exposure and dose are important in determining the extent of the damage caused by a particular teratogen.
- 9. Chromosomal Aneuploidy • • • • • • • „ Nondisjuction resulting in the addition or loss of an entire chromosome „ Deletion of a part of a chromosome „ Microdeletion syndromes (small piece missing which is usually only detected using special techniques)
- 10. Common Chromosomal Syndromes caused by Nondisjuction • • • • • „ „ „ „ „ Down syndrome (trisomy 21) Patau syndrome (trisomy 13) Edwards syndrome (trisomy 18) Turner syndrome (monosomy X) Klinefelter syndrome (47,XXY)
- 11. Conclusion • • • • • • • „ There are many factors which are involved in the formation of structures . „ They interaction between genetics and environment is essential especially during early developmental stages