CONTENT
it is clear that this blog is quite
extensive but you can easily find the point you want.
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What is a chromosome?
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Structure
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Genetically transmitted diseases
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Chromosome 8
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Diseases caused by mutations on
Chromosome 8
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Microcephaly
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Papillary thyroid carcinoma
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Scurvy
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Werner
syndrome – Progeria
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Achromatopsia
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Lymphoma no Hodkin
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Renal
carcinoma
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Burkitt Lymphoma
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To remember
What is a Chromosome?
The chromosomes (which means "colored
bodies" for the intensity with which set certain colors to be dyed to
observe under a microscope), are a component of the cell nucleus that only
appear when the cell is dividing either mitosis or meiosis, and are composed of
proteins and nucleic acids. 
Chromosomes are composed of two DNA
strands which are repeated espiralizan and are held together, so that on one
chromosome are two parts that are identical and are called chromatids, which
are joined by a point called centromere. The centromere divides into two parts
chromatid called ARMS
A chromosome is the structure
resulting from the packaging of DNA and proteins prior to cell division for
further segregation into daughter cells.
Humans have 23 pairs of chromosomes
The nucleic acid (DNA), which owns
the chromosome is divided into small units called genes. These determine the
hereditary characteristics of the cell or organism. The cells of individuals of
a given species usually have a fixed number of chromosomes in higher animals
and plants are presented in pairs.
Structure
In the cell the chromosomes come
in pairs. One member of each pair comes from the father's sperm cell and the
other member of the pair comes from the egg cell of the mother.
In other words, the baby receives half of the genetic material from the
mother and half from the father
FORMATION OF A duplicated chromosome with two chromatids
Genetically transmitted disease
Genetically transmitted disease
Failures or anomalies in the genetic sequence are responsible for
several disorders or diseases of genetic transmission,
Errors which rarely occur during replication of DNA are mutations that
cause suffering chromosomes. These mutations can also be caused by high
temperatures, radiation and various chemicals. Most chromosomal abnormalities that
impair the holder body. These mutations are transmitted hereditarily and for
this reason, the number of carriers of mutated genes
tends to increase due to the reproduction of species, but also tends to
decrease because individuals with genetic mutations do not survive or reproduce
less than their peers.
Genes that cause chromosomal mutations are mostly dominant genes. A
person with just one copy of the recessive gene is determined as a carrier, as
this person has the gene but is not affected by the. In the figure above the
green represents the dominant gene and blue bearer.
Some types of chromosomal mutations are monosomy, disomy, trisomy, the
euploidía, aneuploidy, chromosomal aberration, down syndrome, klinnefelter
syndrome, Turner syndrome, deficiency chromosomal translocation and inversion .
Referred abnormalities tend to produce severe disabilities depending which
affects chromosome pair. As a group, these disorders affect chromosome 7 per
1000 infants.
Structural chromosomal abnormalities
If a break occurs in the chromosome material, it can be recovered. If a
fragment is removed, the material can disappear (deletion), transposed to
another chromosome (translocation) or inserted abnormally (investment)
Major structural alterations of chromosomes.
chromosome 8
Have been reported more than 40 cases of inverted duplication of the
short arm of chromosome 8. As in most chromosomal syndromes, the phenotype
described children with this anomaly is variable and includes facial anomalies,
agenesis of the corpus callosum, hypotonia, neonatal feeding problems, kidney
and heart abnormalities, multiple minor anomalies and severe mental
retardation, which is an alteration present in 100% of cases. Many patients
with this chromosomal abnormality have supported life, so they grow up, but had
a significant mental retardation.
We present 2 cases of inverted duplication of the short arm of
chromosome 8, in which the birth was described agenesis of corpus callosum,
along with other malformations.
CASE 1
For comprencion the following cases are clear you have some scientific
concepts that have been highlighted in the text.
Blood relatives: Applies to the person who is descended from the same
ancestors as another.
BRAIN lateral ventricles. The lateral ventricles are in the cerebral hemispheres.
Each lateral ventricle consists of a triangular central body and four horns.
The lateral ventricles communicate with the third ventricle through the model
is called interventricular hole
Newborn male product of the third pregnancy of a nonconsanguineous
healthy parents, both 32 years old. The first pregnancy ended in a spontaneous
abortion and the second in a healthy girl. The gestation of the index case was
controlled, ultrasound detected a dilated lateral ventricles brain and a
possible lack of the corpus callosum brain, so at 31 weeks of gestation,
underwent fetal blood sampling dare the mother's abdomen . which revealed a
"material increase in the short arms of chromosome 8". Delivery was
spontaneous at 37 weeks of gestation, and birth tail'' vulgar''.
At the time of birth, the child weighed 2335 g had a length of 49 cm and
a head circumference of 31.5. On examination at birth showed a peculiar
phenotype, with hair on the forehead, small nose and large eyes sunken root,
aquiline nose, large mouth with prominent upper lip shaped tent with slight
distortion from the corner to the left, with tongue falling back, high and
narrow palate difficult nasal breathing, decreased muscle tone, frog position
and decrease the intensity of a reflection to the appropriate stimulus.
}
chromosome 8
It contains about 1400 genes, with 140 million base pairs: some of the
diseases associated with chromosome 8 are:
Diseases due to mutations on chromosome 8
Locus Disease
8pter-p22
|
ceroid lipofuscinosis
|
8p23
|
microcephaly
|
8p23.1
|
Malignant fibrous histiocytoma
|
8p22. 16q23.3-q24.1, 13q12.11, 9q32, 3p22-p21.3, 3p22
|
Esophageal squamous cell carcinoma
|
8p22
|
Prostate cancer susceptibility
|
8p22-p21.3
|
Papillary thyroid carcinoma
|
8p22-p21.3
|
Farber lipogranulomatosis
|
8p21.1
|
scurvy
|
8p12-p11.2
|
Werner Syndrome
|
8p12
|
Wolf-Hirschhorn Syndrome
|
8p22-p11
|
Susceptibility to schizophrenia
|
8p11.2
|
Lipoid adrenal hyperplasia
|
8q21-q22
|
Color Blindness
|
8q21.3-q22
|
Linfoma no Hodgkin
|
8q24
|
Hemolytic anemia due to glutaton-reductase deficiency
|
8q24.1
|
renal Carcinoma
|
8q24.11-q24.13
|
chondrosarcoma
|
8q24.12
|
tricorrinofalángico Syndrome
|
8q24.3
|
Hereditary Neuropathy, Lom type
|
8q24.3
|
Rothmund-Thomson
|
8q24
|
Burkitt Lymphoma
|
8q24
|
Juvenile Paget's Disease
|
Locus. It is the place of each gene along a chromosome (the plural is
loci).
DISEASES
MICROCEPHALY
Microcephaly is a congenital condition in which the baby's
head is much
smaller compared to that of a normal child
of the same age and sex.
"Micro" means small and "cephaly"
refers to the head. Most
children with microcephaly also have a small
brain and mental retardation.
However, it should be noted that some
children with small heads have normal
intelligence.
What are the causes of microcephaly?
* Microcephaly can be caused by exposure to harmful substances
during
fetal development or it may be associated with inherited genetic
problems or
syndromes.
* Theories suggest that the following factors may predispose
the fetus
to problems that affect the normal development
of the head during pregnancy:
What are the symptoms of microcephaly?
Listed below are the most common symptoms of microcephaly. However, each
child may experience symptoms differently. Symptoms may include:
* appearance of the baby's head very small
* pitched cry
* poor nutrition
* seizures
* greater movement in the arms or legs (spasticity)
* developmental delay
* mental retardation
* The symptoms of microcephaly may resemble other conditions or
medical
problems. Always consult your child's physician for a diagnosis.
Papillary thyroid carcinoma
Cancer
or thyroid papillary carcinoma is a disease which arises from the thyroid
gland, the thyroid cartilage located below, in front of the neck. The thyroid,
a butterfly-shaped, has two lobes, the right lobe and the left lobe, which are
joined by a narrow isthmus.
There
are three types of treatment for thyroid cancer: surgery, the use of
radioactive iodine and other complementary medicines
The
surgery is done to remove as much cancer as possible and the larger the tumor,
the greater the amount of thyroid gland must be removed. Often, the entire
gland is removed.
After
surgery or radioactive iodine, the patient will need to take a drug called
levothyroxine sodium for the rest of his life, which replaces the thyroid
hormone normally make.
Lack of vitamin C
Scurvy is a deficiency disease
resulting from insufficient intake of vitamin C, which is necessary for the
correct synthesis of collagen in humans. Scurvy leads to the formation of
purple spots on the skin, bleeding gums spongy all mucous membranes. affected
person becomes pale, feels depressed, and is partially immobilized. In advanced
scurvy there are open wounds festering and tooth loss. In addition,
significantly worsens all other diseases, even the most benign, sometimes
making them deadly.
Werner
syndrome – Progeria
The most severe form of this disease is
called Hutchinson-Gilford syndrome, named in honor of Jonathan Hutchinson, who
was first described in 1886 and Hastings Gilford who conducted various studies
on its development and features in 1904.
Werner syndrome has several physical and
mental symptoms .
Short stature
Dry and wrinkled
Premature Baldness
Canas in childhood
Prominent eyes
Skull large
outstanding
Lack of eyebrows and eyelashes
large nose and a peaked
receding chin
Heart problems
narrow chest, with ribs labeled
Tip
thin and skeletal
Narrowing of the coronary arteries
large and stiff joints
Skin spots similar to those of old age by poor metabolism of melanin
Presence of degenerative diseases like arthritis of old age
Natural death at age 13.
Achromatopsia
Color
blindness or vision without color occurs as a result of genetic inheritance and
when an area of the visual cortex in the brain is injured by a TBI. Specifically area
extraestridada cortex, patients describe their vision as similar to a black and
white film.
Color blindness is a recessive
hereditary disease. Color blindness is not degenerative or lead to blindness.
Involving the X chromosome, the gene that causes the disease has been localized
to Xq28.
It is a rare disease, affecting
1/30.000. You can see but you lose the ability to see in color. It also uses
the same term if there is vision in black and white as a result of a head
injury that affects extrastriate cortex.
• Full Color blindness: you lose
the ability to see color, the colors are perceived gray shades lighter or
darker.
• Color blindness incomplete: it
distinguishes a hue and has greater visual acuity.
NHL
NHL
It is a cancer of the lymphoid
tissue, which includes the lymph nodes, spleen and other organs of the immune
system.
There are many different types of
non-Hodgkin lymphomas
and are classified according to how fast the cancer
spreads.
• The cancer may be low grade (slow
growing), intermediate grade or high grade (fast growing). Burkitt's tumor is
an example of high-grade lymphoma. Follicular lymphoma is a low grade lymphoma.
• Cancer is further sub look at the
way the cells under the microscope, for example, if there are certain proteins
or genetic markers present
Symptoms may include:
• Night sweats (soaking the bed
sheets and pajamas though the temperature is not too high)
• Intermittent fever and chills
• Itching
• Swollen lymph nodes in the neck,
armpits, groin, or other areas
• Weight loss
There may be coughing or difficulty
breathing if the cancer
affects the thymus or lymph nodes in the chest, which
can put pressure on the trachea or other airway.
Some patients may have abdominal
pain or swelling,
which can lead to loss of appetite, constipation, nausea and
vomiting.
If the cancer cells in the brain,
the person may experience headaches, concentration problems, personality
changes or seizures.
RENAL CARCINOMA
Renal cell carcinoma is the most common type of kidney cancer in adults
and occurs most often in people 50 to 70 years old.
Not exactly known cause.
The following factors may increase the risk of kidney cancer:
• Dialysis treatment.
• Family history of the disease.
• Hypertension.
• Horseshoe kidney.
• Polycystic kidney.
• Smoking.
• von Hippel-Lindau disease (an inherited disease that affects the blood
vessels of the brain, eyes and other body parts).
symptoms
• Bloating and abdominal pain
• Back pain
• Blood in the urine
• Swelling of the veins around the testicle (varicocele)
• Flank pain
• Weight loss
Other symptoms that may occur include:
• Excessive hair growth in women
• Pale
• Vision problems
Burkitt
Burkitt lymphoma can be noticed as a swelling of the lymph nodes in the
neck, groin or under the arm. Often these swollen lymph nodes are painless, but
they can grow very quickly.
In the most common types seen in the United States, the cancer usually
starts in the abdominal area. The disease can also start in the ovaries,
testes, brain and cerebrospinal fluid.
Symptoms include:
• Nodes that grow together to form a tumor
• Lymph nodes insensitive
• Rapid growth of lymph nodes
• Unexplained swollen lymph nodes
NHL
NHL
NHL
