Human Genetic Disorders 7th Grade Science Mr. Bombick

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Human Genetic Disorders7th Grade ScienceMr.
Bombick
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Major Categories of Genetic Disorders

• Point Mutations
• Gene(s) Deletion(s)
• Chromosomal Aberrations
• Polygenic

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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

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Examples of Genetic Disease Resulting from Point
Mutations

• Cystic Fibrosis
• Huntingtons Disease
• Color Blindness (sex-linked)
• Hemophelia (sex-linked)
• Sickle-Cell Disease (incomplete dominance)
• Phenylketonuria (PKU)
• Tay-Sachs Disease
• Crohns Disease

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Examples of Genetic DiseaseResulting from
Gene(s) Deletion(s)

• Duchenne Muscular Dystrophy (sex-linked)
• Cri du chat
• Cystic Fibrosis
• DiGeorge Syndrome

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Types of Chromosomal Aberrations

• Chromosomal rearrangement
• Extra chromosomes
• Chromosomal deletions

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Examples of Genetic DiseaseResulting from
Chromosomal Aberrations

• Down syndrome (Trisomy of 21)
• Kleinfelters syndrome (XXY)
• Turner syndrome (single X)
• Triple XXX syndrome
• Philadelphia chromosome translocation-chronic
  myelogenous leukemia (CML)

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Examples of Genetic Diseasefrom 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 persons
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.
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Examples of Polygenic Genetic Disorders

• Asthma
• Auto-immune diseases (e.g., MS)
• Cancers
• Cleft palate
• Diabetes
• Heart disease
• Hypertension
• Inflammatory bowel disease
• Mental retardation
• Mood disorders
• Obesity
• Infertility

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The End