ABNORMALITIES OF THE NEWBORN. BABY.pptx

Pediatrics

1. ABNORMALITIES OF THE NEWBORN BABY

2. CHROMOSOMES AND GENE ABNORMALITY INHERITED DISORDERS: The fundamental unit of inheritance is the GENE Genes are packed tightly in chromosomes and are present in all the nucleated cells (exception are the red blood cells which have no nucleus and gametes) A chromosome is a thread like structure of nucleic acids and protein found in the nucleus of most living cells

3. CHROMOSOME

4. INHERITENCE (cont) Two threads are joined together to form a chromosome. The point at which the threads are joined together is known as CENTROMERE. The threads are known as CHROMATIDS. In other words a chromosome is a made up of a pair of chromatids joined in the middle by a centromere The human cell has 46 chromosomes that can be arranged as 23 pairs Each chromosome is one of the pair one inherited from the father and another from mother

5. INHERITENSE (cont) A cell with 23 pars of chromosomes is termed as DIPLOID Gametes (spermatozoa and ova) with only half of the normal complement i.e. 23 chromosomes instead of 46 is termed as HAPLOID Chromosomes belonging to the same pair are called homologous chromosomes A complete set of chromosomes from a cell is its KARYOTYPE

6. INHERITENCE Numbering of chromosomes is arranged from the largest to the smallest. The largest pair being no 1 The first 22 pairs are collectively called as autosomes and the chromosomes of each pair are identical The chromosomes of pair 23 are called the sex chromosomes because they determine the sex of the individual or gender

7. INHERITENCE NOTE: Unlike the autosomes , these two chromosomes are not necessarily identical. There are two types the X and Y. The Y chromosome is much shorter than the X chromosome XX is female and XY the male A child inheriting an X from his mother and a Y from his father is male and a child inheriting two X chromosomes from her parents is female

8. GENES(DNA) GENES are composed of very long strands of DNA DNA is a double stranded molecule made up of two chains of nucleotide. DNA is sometimes likened to a twisted ladder. Nucleotides consist of three subunits - sugar - base - phosphate

9. INHERITENCE GENETIC CODE: DNA carries huge amounts of information that determines all the biological activities of an organism and which is transmitted from one generation to the next. During cell division, (meiosis) each pair divides so that each gamete receives a single or haploid set. Fertilization results in restoration of diploid chromosome constitutions

10. INHERITENCE ANY ABERRATION of the chromosomes resulting in loss or gain of chromosome material is likely to result in mental and physical anomalies. Alterations in the sex chromosome constitution are generally less deleterious

11. DISORDERS Disorders in which genetic factors are implicated can be considered under the following three headings - Chromosomal - Single gene - polygenic or multifactorial

12. DISORDERS Chromosomal abnormalities: Down’s syndrome( trisomy 21) Edwards’ syndrome( trisomy 18) Patau syndrome ( trisomy 13) Turner syndrome (45X) Klinefelters syndrome(47 XXY)

13. DOWN SYNDROME

14. EDWARD SYNDROMEE

15. PATAU SYNDROME

16. TURNER SYNDROME

17. KLINIFELTER SYNDROME

18. SINGLE GENE DISORDERS When a certain gene is known to cause a disease we refer to it as single gene disorder or a Mendelian disorder. Examples are; - Sickle cell disease - Fragile X syndrome - Muscular dystrophy - Cystic fibrosis

19. POLYGENIC or MULTIFACTORIAL Many conditions , including malformations such as spina bifida, hypertension, diabetes schizophrenia in adults show a clear familial tendency which does not conform to any recognizable mode of singe gene inheritance. It is postulated that these disorders result from the interaction of the underlying familial predisposition controlled by many genes at different loci with possible adverse environmental factors.

20. SPINA BIFIDA: MENINGOMYELOCOELE

21. TERATOGENIC FACTORS Teratogenic factors are those which induce congenital malformations or birth defects. They include infections, physical, chemical, drugs, hormonal etc. teratogenic agents during the first weeks of gestation are likely to kill the embryo rather than cause congenital malformations

22. TERATOGENIC FACTORS DRUGS: - antineoplastic agents - sex hormones(progesterone and oestrogens ) TOXINS: - alcohol - heroin - cocaine

23. INFECTION: - rubella - cytomegalo virus - toxoplasmosis MATERNAL: - diabetes - hyperthyroidsm

24. IRRADIATION: - X-rays - radio-iodine COMPRESSION : - oligohydramnos - abnormal uterus

25. OTHER DEFECTS COMMONLY SEEN AT KCMC NEONATAL WARD

26. CNS DEFECTS: ANENCEPHALY/

27. ABDOMINAL DEFECTS: OMPHALOCOEL

28. ABDOMINAL DEFECTS: GASTROSCHISIS

29. MUSCULOSKELETAL: TALIPES EQUINOVARUS

30. MUSCULOSKELETAL: TALIPES CALCANOVALGUS

31. GENITAL URINARY: HYPOSPADIAS

32. CHOANAL ATRESIA

33. CLEFT LIP

34. CLEFT LIP (cont.)

35. HYDROCEPHALUS