Preimplantation Genetic Screening (PGS)

Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a rapidly progressive form of muscular dystrophy that occurs primarily in boys. It is caused by a mutation in a gene, called the DMD gene, which encodes the muscle proteindystrophin. Boys with Duchenne muscular dystrophy do not make the dystrophin protein in their muscles. Duchenne mucular dystrophy is inherited in an X-linked recessive fashion; however, it may also occur in people from families without a known family history of the condition. Individuals who have DMD have progressive loss of muscle function and weakness, which begins in the lower limbs.[1] In addition to the skeletal muscles used for movement, DMD may also affect the muscles of the heart.[2] There is no known cure for Duchenne muscular dystrophy. Treatment is aimed at control of symptoms to maximize the quality of life.

Inheritance

Duchenne and Becker muscular dystrophy are inherited in an X-linked recessive manner. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cellis sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.[4]
In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry a DMD mutation may have muscle weakness and cramping. These symptoms are typically milder than the severe muscle weakness and atrophy seen in affected males. Females who carry a DMD mutation also have an increased risk of developing heart abnormalities including dilated cardiomyopathy.[4]
In about two thirds of cases, an affected male inherits the mutation from a mother who carries an altered copy of the DMD gene. The other one third of cases probably result from new mutations in the gene.[4]

Diagnosis

Duchenne muscular dystrophy (DMD) is suspected and diagnosed when the following clinical findings are found: a positive family history of DMD, more men affected that women in a family, progressive muscle weakness which is usually greater in the proximal muscles (closest to the trunk of the body) than distal muscles (those farthest away from the hips and shoulders such as those in the hands, feet, lower arms or lower legs), symptoms before the age of 5 years old and wheel chair dependency before age 13.

Testing for DMD includes: a blood test which measures the levels of serum creatine phosphokinase (CPK); electromyography which is used to distinguish conditions that only impact the muscles (myotonic) from those that involve that brain and muscles (neurogenic); a skeletal muscle biopsy which is used to detect the presence of specific proteins with a visible label (immunohistochemistry) and molecular genetic testing for deletions, duplications, rearrangements, etc. of genetic material.[5]

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

 

Thalassemia

thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen. The disorder results in large numbers of red blood cells being destroyed, which leads to anemia.
Causes
Hemoglobin is made of 2 proteins:

  • Alpha globin
  • Beta globin

Thalassemia occurs when there is a defect in a gene that helps control production of 1 of these proteins.
There are 2 main types of thalassemia:

  • Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or changed (mutated).
  • Beta thalassemia occurs when similar gene defects affect production of the beta globin protein.

Alpha thalassemias occur most often in people from Southeast Asia, the Middle East, China, and in those of African descent.
Beta thalassemias occur most often in people of Mediterranean origin. To a lesser extent, Chinese, other Asians, and African Americans can be affected.
There are many forms of thalassemia. Each type has many different subtypes. Both alpha and beta thalassemia include the following 2 forms:

  • Thalassemia major
  • Thalassemia minor

You must inherit the gene defect from both parents to develop thalassemia major.
Thalassemia minor occurs if you receive the faulty gene from only 1 parent. People with this form of the disorder are carriers of the disease. Most of the time, they do not have sym
Risk factors for thalassemia include

  • Asian, Chinese, Mediterranean, or African American ethnicity
  • Family history of the disorder

Symptoms
The most severe form of alpha thalassemia major causes stillbirth (death of the unborn baby during birth or the late stages of pregnancy).
Children born with beta thalassemia major (Cooley anemia) are normal at birth, but develop severe anemia during the first year of life.
Other symptoms can include:

  • Bone deformities in the face
  • Fatigue
  • Growth failure
  • Shortness of breath
  • Yellow skin (jaundice)

People with the minor form of alpha and beta thalassemia have small red blood cells but no symptoms.
Exams and Tests
Your health care provider will do a physical exam to look for an enlarged spleen.
A blood sample will be sent to a laboratory to be tested.

  • Red blood cells will appear small and abnormally shaped when looked at under a microscope.
  • A complete blood count (CBC) reveals anemia.
  • A test called hemoglobin electrophoresis shows the presence of an abnormal form of hemoglobin.
  • A test called mutational analysis can help detect alpha thalassemia.

Treatment
Treatment for thalassemia major often involves regular blood transfusions and folate supplements.
If you receive blood transfusions, you should not take iron supplements. Doing so can cause a high amount of iron to build up in the body, which can be harmful.
sibling if you have a family history of the condition and are thinking of having children.

Possible Complications

Untreated, thalassemia major leads to heart failure and liver problems. It also makes a person more likely to develop infections.
Blood transfusions can help control some symptoms, but carry a risk of side effects from too much iron.

Preimplantation Genetic Diagnosis for BRCA Mutation Carriers

For women who have a strong family incidence of breast cancer, this science has proved useful by identifying the BRCA1 or BRCA2 gene. Women who test positivefor a mutation of one of these genes have a greatly increased chance of developing breast and ovarian cancer during their lifetimes.
For women who have a strong family incidence of breast cancer, this science has proved useful by identifying the BRCA1 or BRCA2 gene. Women who test positivefor a mutation of one of these genes have a greatly increased chance of developing breast and ovarian cancer during their lifetime

If you’ve tested positive for a mutation in the BRCA1 or BRCA2 gene — or some other inherited gene mutation associated with increased risk of breast cancer and possibly other cancers — it’s natural to be concerned about passing the mutation along to your biological children. There’s a 50% chance that any child you have will inherit the mutation. The same holds true if you are not a mutation carrier but your part
Some women of childbearing age are now choosing to use preimplantation genetic diagnosis, or PGD, to ensure they won’t pass a BRCA1 or BRCA2mutation on to their children. (PGD also can be used in cases of other cancer-related mutation

Cystic fibrosis

Cystic fibrosis is an inherited disease that causes symptoms like frequent lung and sinus infections, failure to thrive as an infant, and frequent, oily stools from fat malabsorption.if we  explore the inheritance pattern of cystic fibrosis, as well as the statistical chances of a child developing CF if both parents are CF carriers.

Cystic Fibrosis: Autosomal Recessive Disease.

Cystic fibrosis is caused by a mutation of the cystic fibrosis transmembrane regulator (CFTR) gene. If you are a CF carrier, it means that one of your CFTR genes is normal, and the other contains a mutation that is known to cause cystic fibrosis.
Cystic fibrosis only occurs when both copies of the CFTR gene contain a mutation—this is why cystic fibrosis is called an autosomal recessive disease, as opposed to an autosomal dominant disease in which only one copy of the mutated gene is needed for disease development.
The bottom line is if you and your partner are both CF carriers, you could pass CF on to your child.
This is because your child will inherit one chromosome of each pair from you, and one from your partner. If your child gets both copies of the chromosome containing the mutated CFTR gene, they will have two mutated copies and will be born with cystic fibrosis.
If your child inherits a mutated chromosome from one of you and a normal one from the other, they will be a CF carrier.
If your child inherits the normal chromosome from both of you, he will have two normal copies meaning he neither carries nor has CF.

Cystic Fibrosis Carriers: Statistics

The possible combinations that two CF carriers can pass onto their child are:

  • Normal CFTR from mom + mutation from dad = carrier
  • Normal CFTR from dad + mutation from mom = carrier
  • Normal CFTR from mom + normal CFTR from dad = not a carrier and does not have CF
  • Mutated CFTR from mom + mutated CFTR from dad = cystic fibrosis

If you and your partner are both carriers, your child has a 25 percent chance of having CF, a 50 percent chance of being a carrier, and a 25 percent chance of neither having nor carrying CF.
If your partner is not a CF carrier, it will be impossible for your child to have CF because he can only inherit normal copies of the CFTR gene from your partner. However, your child will have a 25 percent chance of being a carrier, which would occur if they received the mutated CFTR gene from you—and this means your child could then pass on the CF trait to their children.  

Cystic Fibrosis Carriers: Health

If you are a CF carrier, you will have no symptoms of cystic fibrosis and do not have to worry about developing cystic fibrosis.
In addition, being a CF carrier will not shorten your life or limit you in any way (with the exception of family planning).
When you do start thinking about having children, you and your partner should seek genetic counseling to determine your combined risk of passing CF on to your future children. You can see if you and your partner are CF carriers by undergoing a blood test to check for the CF gene. 

A Word From Verywell

Prior to newborn screening programs, the majority of people did not find out they had CF until they had symptoms (usually in childhood). If an infant has a positive CF newborn screening test, he or she will undergo a  sweat chloride test to confirm the diagnosis of CF.

In this test, the salt content of the baby's sweat is measured. People with CF have an abnormally high level of salt in their sweat because of impaired sweat gland function. 
But with pgs that we are offering in our center, u can detect cftr gene and thus CF even before  conception. Thus after ivf procedure only healthy embryos without CF gene are selected and implanted,thus giving only healthy babies to couples.

Down Syndrome

What is Down Syndrome?
Down syndrome is the most common genetic condition affecting 1 in every 691 babies born in the United States. Roughly 6,000 babies are born each year with Down syndrome and that number is expected to rise given that women are starting their families later in life. Approximately 400,000 Americans currently have Down Syndrome.
down-syndrome-pgd-pgs-orange-county-nihgov photoEach human cell has 46 chromosomes with 23 inherited by the mother and 23 inherited by the father. Down syndrome, also known as Trisomy 21, occurs when 3 chromosomes occur at the 21 position instead of the normal 2 chromosomes. In other words, in chromosome 21, there is an extra copy giving rise to 47 chromosomes instead of the normal 46. This extra chromosome alters the development stage and causes characteristics of Down syndrome which are small stature, low muscle tone, flattened facial profile, upward slant to the eyes, and a deep crease across the center of the palm.
Maternal Age and Down Syndrome
– A 28 year old woman has about a 1 in 1,000 chance of conceiving a baby with Down syndrome.
– A 32 year old woman has about a 1 in 720 chance of conceiving a baby with Down syndrome.
– A 36 year old woman has about a 1 in 300 chance of conceiving a baby with Down syndrome.
– A 40 year old woman has about a 1 in 100 chance of conceiving a baby with Down syndrome.
There are screening and diagnostic tests that can be performed before the baby is born to determine his or her chances of having Down syndrome.
Preimplantation Genetic Diagnosis and Down Syndrome
west-coast-fertility-center-down-syndrome-trisomy21-pgd photo
Preimplantation Genetic Diagnosis (PGD) allows for the selection of the best quality embryos before IVF, thus reducing the incidence of a chromosomally abnormal offspring. After fertilization of the egg and sperm in the laboratory, one cell is removed from each embryo during its third day of development. PGD with use of a special fluorescent microscope can detect any extra chromosomes or any missing chromosomes that are related with birth defects.

If you have a family history of genetic chromosomal disorders, recurrent miscarriages, u can consult in our hospital for PGS to diagnose down syndrome.