Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Human Diseases A Systemic Approach Sixth Edition Chapter 5 Heredity and Disease Mary Lou Mulvihill Mark Zelman Paul Holdaway Elaine Tompary Jill Raymond

Chapter 5 Heredity and Disease Slide 10Sickle Cells Slide 10Sickle Cells Slide 24Down Syndrome Slide 24Down Syndrome Multimedia Asset Directory Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Heredity  DNA – blueprint  45 chromosomes (genes) (alleles)  44 autosomes  2 sex chromosomes: X and Y  Karyotype

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Genetic Inheritance  Alleles – Homozygous – Heterozygous – Dominant – Recessive

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-1: Meiosis.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-2: Normal human karyotype. (©Custom Medical Stock Photo.)

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Table 5-1: Hereditary Disease Locations

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Autosomal Dominant  Transmission of a dominant allele  50% chance of being affected  Disease appears in every generation  Males and females equally being affected

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-3: Transmission of autosomal dominant disorders. (50% chance for an affected child).

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Click on the screenshot to view an animation showing sickle cells. Return to Directory

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Autosomal Dominant Diseases  Polydactyly  Achondroplasia  Marfan’s syndrome  Familial hypercholesterolemia

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-4: A 12-year old Achondroplastic dwarf. Note the disproportion of the limbs to the trunk, the curvature of the spine, and the prominent buttocks.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Autosomal Recessive  Disease manifests when individual is homozygous for the defective allele  Parents are carriers; they do not have the disease  Child has a 25% chance of being affected  Recessive allele appears more frequently in close intermarriages

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-5: Transmission of recessive disorders (25% chance for an affected child).

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Autosomal Recessive Diseases  Phenylketonuria  Galactosemia  Sickle cell anemia  Tay-Sachs disease  Albinism

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Normal red blood cells. (©Phototake NYC.)

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Sickle blood cells. (©Photo Researchers, Inc.)

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-6: Enzyme block in phenylketonuria (PKU)

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Sex-Linked Inheritance  Defective gene on X chromosome  Defective X on male is unmasked and the trait is expressed.  Female is carrier for the disease; heterozygous  Male transmits the defective allele to his daughters.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-7: Transmission of sex-linked disorders.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Autosomal Recessive Diseases  Color blindness: inability to distinguish colors  Hemophilia  Fragile X syndrome – a break or weakness on long arm of X chromosome

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Abnormal Chromosome Diseases  Altered number or structure  Failure of chromosome to separate during cell division  Loss of autosome is usually incompatible with life

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Down Syndrome  Caused by the presence of an extra autosome, nondisjunction  Results in mental retardation and shorter life expectancy  Characteristic appearance: slanted eyes, extra fold of skin at upper medial corner of the eye, protrusion of the tongue, short nose  Short stature, underdeveloped sex organs

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Click on the screenshot to view a video on the topic of Down syndrome. Return to Directory

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-8: Girl with Down syndrome. (©Beebe / Custom Medical Stock Photo.)

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Familial Disease  Diseases run in families but means of inheritance are not understood  Most likely the effects of several genes working together  Examples: diabetes, allergies, familial polyposis

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Cri Du Chat Syndrome  Cat-like cry  Caused by deletion of part of the short arm of chromosome 5  Results in an abnormally small head with a deficiency in cerebral brain tissue  Widely spaced eyes and mental retardation

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Sex Anomalies  Turner’s syndrome: missing sex chromosome  Klinefelter’s syndrome: extra sex chromosome  Hermaphrodite: has both testes and ovaries  Pseudohermaphrodite: has either

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-9: A 21-year-old patient with Turner’s syndrome. The chest is broad and the nipples are small and pale. Pubic hair is totally lacking.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-10: A 19-year-old patient with Klinefelter’s syndrome. Extremities are excessively long, pubic hair is scanty, and genitals undeveloped. Body proportions resemble those of a eunuch.

Mulvihill, Zelman, Holdaway, Tompary, and Raymond Human Diseases: A Systemic Approach, 6e Copyright ©2006 by Prentice-Hall, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 5-11: A 22-year-old patient with pseudohermaphroditism, reared as a girl because of ambiguous genitalia. Surgery and tissue studies showed the gonads to be testes.