Download Human Genetic Disorders 7th Grade Science Mr. Bombick

Human Genetic Disorders
7th Grade Science
Mr. Bombick
Major Categories of Genetic Disorders
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Point Mutations
Gene(s) Deletion(s)
Chromosomal Aberrations
Polygenic
Point Mutations
• Point mutations are changes within a
particular gene
• Point mutations can be the incorrect
insertion or deletion of single
nucleotides
• A point mutation can result in an altered
gene product (protein) or no gene
product (protein) being made
• A point mutation may result in no
abnormality, a lethal situation, or a
genetic disease
Examples of Genetic Disease
Resulting from Point Mutations
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Cystic Fibrosis
Huntington’s Disease
Color Blindness (sex-linked)
Hemophelia (sex-linked)
Sickle-Cell Disease (incomplete
dominance)
• Phenylketonuria (PKU)
• Tay-Sachs Disease
• Crohn’s Disease
Examples of Genetic Disease
Resulting from Gene(s) Deletion(s)
• Duchenne Muscular Dystrophy (sexlinked)
• Cri du chat
• Cystic Fibrosis
• DiGeorge Syndrome
Types of Chromosomal Aberrations
• Chromosomal rearrangement
• Extra chromosomes
• Chromosomal deletions
Examples of Genetic Disease
Resulting from Chromosomal Aberrations
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Down syndrome (Trisomy of 21)
Kleinfelter’s syndrome (XXY)
Turner syndrome (single X)
Triple XXX syndrome
Philadelphia chromosome translocationchronic myelogenous leukemia (CML)
Examples of Genetic Disease
from Complex and polygenic Factors
Genetic disorders may be complex and polygenic
meaning that they are likely associated with the
effects of multiple genes in combination with
lifestyle and environmental factors. Although
complex disorders often cluster in families, they
do not have a clear-cut pattern of inheritance.
This makes it difficult to determine a person’s
risk of inheriting or passing on these disorders.
Complex disorders are also difficult to study
and treat because the specific factors that
cause most of these disorders have not yet been
identified.
Examples of Polygenic Genetic Disorders
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Asthma
Auto-immune diseases (e.g., MS)
Cancers
Cleft palate
Diabetes
Heart disease
Hypertension
Inflammatory bowel disease
Mental retardation
Mood disorders
Obesity
Infertility
The End