The document discusses hypercholesterolemia, providing details on the structure and function of cell membranes, including the fluid mosaic model. It then focuses on familial hypercholesterolemia, explaining that it is a genetic disorder caused by mutations in genes like LDLR that result in very high LDL cholesterol levels and increased risk of early heart disease. The LDLR gene normally allows cells to remove LDL from the blood, but mutations disrupt this process and lead to excess cholesterol building up in arteries.

1. HYPERCHOLESTEROLAEMIA
DISEASE
Zeinab Mohamed Klaab 439204646

2. INTRODUCTION
 Each cell of your body is encased in a tiny bubble of membrane. The cell
membrane which separates the inside of the cell from the outside
environment.
 In general its job; it is borders of the cell, allows the cell to interact with its
environment in a controlled way and able to communicate with other cells,
identifying themselves and sharing information.
 To perform these roles, the plasma membrane needs phospholipids, as the
foundation. It also needs proteins act as a tunnels, which are involved in
cross-membrane transport and cell communication, and carbohydrates which
help cells recognize each other.
 If the cell membrane is unable to do its job properly, this can cause different
dysfunctions of the cell membrane that result in diseases in a person.

3. THE
PLASMA MEMBRA
NE
FLUID MOSAIC
MODEL The fluid mosaic model structure,
was first proposed in 1972 by Singer
and Nicolson. it provides a good basic
description of the structure and
behavior of membranes in many
cells.
 According to this model, the
plasma membrane is a mosaic of
components of proteins and other
molecules are embedded in a
framework of phospholipids. A
membrane is fluid which protein and
phospholipid molecules can move
laterally and it has Flip-Flop
movement is restricted and is
catalyzed by protein “Flippase” that
important during membrane lipid
transferes diffuion

4. 1- CELL MEMBRANE
LIPIDS
 Phospholipids: are a major component of
cell membranes. Phospholipids form a lipid
bilayer in which their hydrophilic head and
hydrophobic tail areas face. The lipid
bilayer is semi-permeable, allowing only
certain molecules to diffuse across the
membrane.
 Cholesterol: helps to keep cell membranes
from becoming stiff by preventing
phospholipids from being too closely packed
together.
 Glycolipids are located on cell membrane
surfaces and have a carbohydrate sugar
chain attached to them. They help the cell
to recognize other cells of the body.

5. 2- CELL MEMBRANE
PROTEINS
 The cell membrane contains two types of
associated proteins.
1. Peripheral membrane proteins are exterior to
and connected to the membrane by
interactions with other proteins.
2. Integral membrane proteins are inserted into
the membrane and most pass through the
membrane.

6. THIS DIAGRAM SHOWS THE
FUNCTIONS OF PROTEINS FOUND IN
THE PLASMA MEMBRANE.

7. 3- CELL MEMBRANE
CARBOHYDRATES
 Carbohydrates are found on the outside
surface of cells and are bound either to
proteins (forming glycoproteins) or to lipids
(forming glycolipids).
 These carbohydrate chains may consist of
2-60 monosaccharide units and can be
either straight or branched.
 carbohydrates form distinctive cellular
markers that allow cells to recognize each
other. These markers are very important in
the immune system, allowing immune cells
to differentiate between body cells.

8. MEMBRANE-RELATED
DISEASES
 As describe a previous, the membranes of mammalian cells are composed of an
ordered array of lipids and proteins, the latter containing carbohydrate residues
directed towards the exterior and important in the interaction of cells with each other
and with external proteins
 In many cases, chemical or functional changes in these membranes are central to the
pathogenesis of the disease.
A classification of membrane-related diseases includes:
 receptor-related diseases such as type II familial hypercholesterolaemia, Grave's disease,
some lysosomal storage diseases and some forms of diabetes and obesity;
 structural instability as changes in lipid state as in muscular dystrophy and multiple
sclerosis;
 altered permeability or transport as in cystic fibrosis, diseases associated with specific
transport defects, and the action of many bacterial toxins,
 and abnormality of the cytoskeleton-membrane interface as in Chediak-Higashi disease and
some diseases associated with red cell abnormalities.

9. FAMILIAL
HYPERCHOLESTERO
LEMIA
 Familial hypercholesterolemia is a genetic
disorder that is passed down through families.
It causes LDL (bad) cholesterol level to be very
high.
 The condition begins at birth and can cause
heart attacks at an early age and is commonly
caused by mutations in low-density lipoprotein
receptor (LDLR), apolipoprotein B (APOB) and
very rarely in LDLR adaptor protein 1
(LDLRAP1) genes.
 The condition is typically passed down through
families in an autosomal dominant manner.
That means you only need to get the abnormal
gene from one parent in order to inherit the
disease.
 Treatments including medications and healthy

10. LDLR GENE (NORMAL FUNCTION(
 The LDLR gene provides instructions for making a protein called the low-density
lipoprotein receptor. This receptor binds to particles called low-density lipoproteins
(LDLs), which are the primary carriers of cholesterol in the blood
 Low-density lipoprotein receptors sit on the outer surface of many types of cells,
where they pick up LDLs circulating in the bloodstream and transport them into the
cell. Once inside the cell, the LDL is broken down to release cholesterol. The
cholesterol is then used by the cell, stored, or removed from the body. After low-
density lipoprotein receptors drop off their cargo, they are recycled back to the cell
surface to pick up more LDLs.
 Low-density lipoprotein receptors play a critical role in regulating the amount of
cholesterol in the blood. They are particularly abundant in the liver, which is the
organ responsible for removing most excess cholesterol from the body.

11. MUTATION FORM
(FAMILIAL
HYPERCHOLESTEROLEMIA)
 Mutations in the LDLR gene cause a form of high cholesterol called familial
hypercholesterolemia.
 More than 2,000 mutations have been identified in this gene. Some of these genetic
changes reduce the number of low-density lipoprotein receptors produced within cells.
Other mutations disrupt the receptor's ability to remove LDLs from the blood.
 As a result, people with mutations in the LDLR gene have very high blood cholesterol
levels. As the excess cholesterol circulates through the bloodstream, it is deposited
abnormally in tissues such as the skin, tendons, and arteries that supply blood to the
heart (coronary arteries). A buildup of cholesterol in the walls of coronary arteries
greatly increases a person's risk of having a heart attack.
 These cases are associated with an increased risk of early heart disease appears in
childhood.

12. Any Questions?