Genetic Disorders due to Error in Meiosis

Genetic Disorders due to Error in Meiosis

1. Errors in Meiosis Prepared by: Ms. Jasmine Nikki M. Versoza

2. Humans have 22 pairs of non-sex chromosomes known as autosomes and one pair of sex chromosomes XX – female XY - male BASIC INFORMATION

3. When a chromosome pair doesn’t separate during meiosis One of the gametes might have an extra chromosome number and others might have few NONDISJUNCTION

4. Having an abnormal chromosome number In human cell, instead of 46 chromosomes in each cell, it might have 45 or 47. ANEUPLOIDY

5. Genetic Disorders Prepared by: Ms. Jasmine Nikki M. Versoza

6. Almost 6% of all babies are born with some form of genetic disorder. Worldwide, that’s about 8 million babies every year DID YOU KNOW?

7. There’s an extra chromosome Trisomy 13 Trisomy 18 Trisomy 21 TRISOMY SYNDROMES

8. Patau Syndrome A serious rare genetic disorder caused by having an additional copy of chromosome 13 in some or all of the body cells. This severely disrupts normal development and, in many cases, results in miscarriage, stillbirth or the baby dying shortly after birth. TRISOMY 13

9. More than 9 out of 10 children born with Patau's syndrome die during the first year. About 1 in 10 babies with less severe forms of the syndrome, such as partial or mosaic trisomy 13, live for more than a year. TRISOMY 13

10. Severe heart defects Holoprosencephaly Cleft lip and palate Microphthalmia TRISOMY 13 Anophthalmia Hypotelorism Problems with the development of the nasal passages SYMPTOMS/FACIAL FEATURES

11. TRISOMY 13 Microcephaly Cutis aplasia Ear malformations and deafness Raised, red birthmarks SYMPTOMS/FACIAL FEATURES

12. TRISOMY 13 Cause Most cases of the syndrome do not run in families. They occur randomly during conception, when the sperm and egg combine and the fetus starts to develop.

13. Edward Syndrome Result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies TRISOMY 18

14. Edwards' syndrome affects how long a baby may survive. Most babies with Edwards' syndrome will die before or shortly after being born. A small number, about 13 in 100, babies born alive with Edwards' syndrome will live past their 1st birthday. TRISOMY 18

15. Symptoms/Facial Features Intrauterine growth retardation Craniofacial features such as abnormalities of the jaw, skull, ears, and neck Clenched fists with overriding fingers Small fingernails TRISOMY 18

16. Symptoms/Facial Features Short sternum Club feet Heart defects Kidney defects Neurodevelopmental delays TRISOMY 18

17. Cause Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm TRISOMY 18

18. Down Syndrome Occurs because of the extra copy of chromosome 21, which can cause the body and brain to develop differently than a child without the syndrome Adults with Down syndrome may live about 60 years, but this can vary. TRISOMY 21

19. SYMPTOMS/FACIAL FEATURES Distinctive facial features Mild to moderate intellectual disabilities Heart, kidney and thyroid issues Numerous respiratory infections Skeletal abnormalities Flexible joints and weak, floppy muscles TRISOMY 21

20. SYMPTOMS/FACIAL FEATURES Overly quiet baby Less responsive to stimuli Vision and hearing impairment Inwardly curved little finger TRISOMY 21

21. A genetic disorder wherein there’s a missing chromosome Example: Turner Syndrome or Monosomy X The affected individual has only one X chromosome. In other cases of Turner syndrome, there may be only part of the second X chromosome missing, or it may have a structural abnormality. MONOSOMY DISORDER

22. Turner Syndrome A rare genetic disorder that occurs in girls The seriousness of these problems varies from girl to girl. Many of the health problems affecting girls with Turner syndrome can be managed or fixed with treatment. MONOSOMY X

23. SYMPTOMS/FACIAL FEATURES Puffy hands and feet at birth Wide neck with folds of skin down the sides of neck Short height A low hairline at the back of the neck Feeding problems as a baby Small differences in the shape and position of the ears MONOSOMY X

24. SYMPTOMS/FACIAL FEATURES Broad chest with widely spaced nipples More small brown moles on the skin than normal Deep-set nails Small jaw Narrow top of the inside of the mouth Skeletal problems Eye problems requiring glasses MONOSOMY X

25. https://letstalkscience.ca/educational-resources/stem-in-context/meiosis-mistakes https://www.acog.org/patient-resources/faqs/pregnancy/genetic-disorders#:~:text=A%20common%20trisomy%20is%20trisomy,missing%20or%20damaged%20X%20chromosome . https://www.nhs.uk/conditions/pataus-syndrome/ https://medlineplus.gov/genetics/condition/trisomy-18/#resources https://www.stanfordchildrens.org/en/topic/default?id=down-syndrome-trisomy-21-90-P02356 https://www.cdc.gov/ncbddd/birthdefects/downsyndrome.html REFERENCES: