GENE DEFECTS

1
GENE DEFECTS

• DOMINANT
• RECESSIVE
• SEX-LINKED
• CROMOSOMAL ABONORMALITIES

2
GENES

• DEFECTS TRANSMITTED BY DOMINANT INHERITANCE
• NORMAL GENES ARE USUALLY DOMINANT OVER ABNORMAL
  TRAITS.
• SOMETIMES A DOMINANT GENE CAN CARRY AN ABNORMAL
  TRAIT.
• WHEN ONE PARENT HAS ONE DOMINANT NORMAL AND ONE
  DOMINANT ABNORMAL GENE AND THE OTHER PARENT HAS
  TWO NORMAL GENES, THEN THERE IS A 50 CHANCE OF
  EACH CHILD INHERITING THE ABNORMAL GENE.
• NOT LIFE THREATENING BEFORE THE AGE OF
  REPRODUCTION (COULD NOT BE PASSED ON).

3
GENES

• 1800 DISORDERS
• TWO
• ACHONDROPLASIA (DWARFISM)
• HUNTINGTONS DISEASE
• GENOME IMPRITING
• GENE TEMPORARILY IMPRINTED, OR CHAMICALLY ALTERED
  IN MOTHER OR FATHER.
• DIFFERENT EFFECTS. IMPRINTED GENE DOMINATES A
  GENE THAT HAS NOT BEEN IMPRINTED.
• INHERITANCE FROM FATHER HAS EARLIER AFFECT THEN
  FROM MOHTER.

4
GENES

• DEFECTS TRANSMITTED BY RECESSIVE INHERITANCE
• CAN BE KILLERS EARLY IN LIFE.
• SICKLE-CELL TAY-SACHS (MORE ETHINIC ORIENTED AND
  INBRED).
• CHILD RECEIVES THE SAME RECESSIVE GENE FROM EACH
  PARENT (IF FATHER IS HOMOZYGOUS, TWO ALLELES FOR
  THE TRAIT, HE HAS THE DISORDER. HETEROZYGOUS,
  ONE NORMAL AND ONE DEFECTIVE ALLELE, HE IS A
  CARRIER).
• NONE OF THE CHILDREN WILL HAVE IT, BUT THE
  CHILDREN WILL BE CARRIERS.
• IF BOTH THE PARENTS CARRY THE ABNORMAL RECESSIVE
  GENE, THEY ARE UNAFFECTED. THE CHILD WILL HAVE A
  25 CHANCE OF INHERITING THE ABNORMAL GENE AND
  SUFFER THE DISORDER AND ALSO HAVE A 50 CHANCE OF
  BEING A CARRIER.

5
GENES

• DEFECTS TRANSMITTED BY SEX-LINKED INHERITANCE
• COLOR BLINDNESS. INHERITED FROM MOTHER.
• RED-GREEN COLOR BLINDNESS AND HEMOPHILIA.
• SEX-LINKED RECESSIVE TRAITS ARE GENES ON THE SEX
  CHROMOSOMES AND TRANSMITTED DIFFERENTLY TO MALE
  AND FEMALE CHILDREN.
• CHROMOSOME ABNORMALITIES
• SOME INHERITED SOME ACCIDENT
• SEE PAGE 51