Pardis Genetic Counselling

Genetic counseling
Types of Disabilities
Defining Genetic Counseling
The need for genetic counseling
Period for conducting genetic counseling
Individuals referred for genetic counseling
Familial marriage in a family with a history of disabled person in the family
Non-familial marriage without any disabled person in the family
Non-familial marriage with a history of disabled person in the family
Teratogens (Disorder causing substances)
Prenatal diagnostic methods
Genetic counseling

In Iran, seven out of every 10 people have disabilities. Individuals who have difficulties in hearing, speech, learning, movement, behavioral abnormalities and sensory disorders of organs are called disabilities

Types of Disabilities
  • Physical disability (motor-visual-hearing)
  • Mental impairment

Genetic and congenital diseases, infectious and noninfectious diseases, and environmental factors can cause disability. It is possible to prevent disabilities before pregnancy, during pregnancy and after birth.

Defining Genetic Counseling

The most important goal of genetic counseling is to determine the genetic problems in a family and determine the risk of its recurrence in subsequent pregnancies.

Genetic counseling helps those who:

  • Understand the reality of their medical problems.
  • Figure out how the illness is being inherited and its possible re-occurrence in relatives.
  • Being acquainted with the symptoms and complications of the disease and its consequences.
  • Identify ways to deal with the problem (such as pre-birth diagnostic methods and fertility methods) and choose a way that is consistent with goals, values and beliefs of the patient.
The need for genetic counseling

In general, it is essential to have genetic counseling in any case which may have a genetic basis. With accurate counselling, inherited or not, the genetics doctor may be able to determine the reasons behind the disorder.

Period for conducting genetic counseling
  • before marriage
  • Pre-pregnancy
  • During pregnancy
  • The best time for genetic counseling is before marriage.
Individuals referred for genetic counseling
  • Family marriage
  • Multiple congenital defects
  • Mental retardation
  • Chronic and progressive neurological diseases
  • Nervous and muscular disorders
  • Dysmophilia and impaired growth
  • Metabolic disorders
  • Abnormal appearance
  • Sexual ambiguity, impairment in puberty
  • Contact with disability and mutagenic causing substances
  • Pregnancy over the age of 35 years
  • Pregnancy under the age of 18 years
  • Cancer, diabetes, and heart disease
  • Ensuring confidentiality for a common, none transferable genetic disorder in the population (thalassemia, anemia, etc.)

Each person has about 30,000 genes within each cell. There may be one or more defective gene in each person, and if a healthy individual with a recessive gene carrying a disorder marries a family member, the disorder will be expressed in their offspring. Today, more than 20,000 types of hereditary disorders are known to occur, which may be due to the inheritance of a common gene from parents in their offspring. In genetic science, individuals are divided into six degrees according to the closeness or distance of kinship and hereditary similarities.

Degree of kinship Family members Percentage of genes shared
۱st Degree Father, Mother, Child, Brother, Sister ۵۰
۲ND Degree Aunt, Uncle, Nephew, Niece, Step sister and step brother, Family marriage (cousins) ۲۵
۳RD Degree Cousin (child of aunt or uncle) ۱۲٫۵
۴TH Degree Grandchildren of Aunts and Uncles, 3rd degree stepfamily ۶٫۲۵
۵TH Degree Great-grandchild of aunts and uncles ۳٫۱۲
۶TH Degree Great-Great-grandchild of aunts and uncles ۱٫۶۴

Researchers now believe that many risk factors occur for woman three months before pregnancy and therefor pregnancy is considered a 12-month period instead of 9 months, as a result:Pre-pregnancy counseling is mandatory for maternal and fetal health.

The best age for women to have children is between the ages of 20 and 30 and for men is between the ages of 20 and 40. Most couples that are referred for genetic counseling before pregnancy, usually recall their parents and relatives, saying: “none of our parents or relatives had a planned pregnancy.” In response, they are informed that,back to back pregnancies may cause various maternal diseases during pregnancy and postpartum, infant mortality and a history of repeated miscarriages, stillbirth and disabilities in the family all due to a lack of family planning. Since the greatest risk for developing fetal abnormalities occurs between the second and eighth week of pregnancy, while the mother only becomes aware that she is pregnant between the third to fifth week of her pregnancy, the importance of pre-natal counseling is more evident. Mother’s age is one of the most important causes of genetic disorders.

A strong correlation is seen between the frequency of Down syndrome, abnormalities in motherhood, a large number of sexual dysfunctions in newborns and parents age. Pre-natal diagnosis of some of the anomalies due to the increase in age of parents may be possible by amniocentesis.

The risk of developing a disorder in offspring is determined by considering the degree of kinship and family marriage. For example, in a marriage with a third-degree relative, such as a cousin, the risk is estimated to be about 5-6%. While are none family related marriage has a base risk of 2-3% and a risk of more than 10% is considered high risk. Therefore, such marriages, although in a low-risk range, still have a twofold equivalent of none family marriage.

In addition, it should be noted that routine testing, taking folic acid and supplementation are essential in pregnancy. In familial marriages, the incidence of recurrent hereditary disorders has increased, therefore the chance of disabilities in offspring increases.

  • Infertility and recurrent miscarriage
  • Concerns about the reoccurring risk of a family history of a disease
Familial marriage in a family with a history of disabled person in the family

The first step when diagnosing a disorder is by performing the necessary tests and providing medical consultation. By diagnosing a person with a disability, the reoccurrence risk of the disease can be determined. The family is advised based on the diagnosis of the disease, determining its degree of inheritance, and the reoccurrence risk. It is essential to perform routine folic acid and supplementation tests.

Non-familial marriage without any disabled person in the family

The probability of similar recessive genes found in non-familial marriage is 2-3%. The occurrence of hereditary diseases depends on the frequency of the gene in the community. Complete vaccination, routine testing and folic acid intake is essential.

Non-familial marriage with a history of disabled person in the family

The presence of a person with disabilities in the family, depending on the type of transmission, changes the risk of disability in children.
The frequency of the gene in the population is important.
Diagnosis of the type of disability and its inheritance is the first step in determining the risk of recurrence of the disease.
Complete vaccination, routine tests and folic acid is required.

Teratogens (Disorder causing substances)

Teratogens are substances that cause congenital anomalies. This substance may be a substance, a medicine, or an infection from the mother’s disease that causes a structural or functional disability in the embryo or fetus. Chemicals and drugs include alcohol, cigarettes, iodine replacement, phenytoin, sodium valproate, tetracycline, lithium, etc., and maternal diseases including phenylketonuria, lupus, and hormonal diseases of the mother.
Rays:
X-rays and other ionizing radiation are harmful.
Unnecessary radiation should be avoided because it changes the cellular inheritance, and splitting and multiplying of cells, including gonads. Ordinary radiological tests (sinuses, respiratory organs, digestive organs, etc.)
It is better not to use specific radiological tests such as IVP, Intravenous Pyelography and barium enema in the first months of pregnancy.
Radiation of the developing fetus can increase congenital anomalies and increase the incidence of leukemia. The mutagens are substances or agents that affect not only the sex cells, but also the somatic cells, which can cause a sufficient amount of DNA changes and the time of carrying genetic information.

Prenatal diagnostic methods

Prenatal diagnosis is a method that can be used to detect diseases and abnormalities in the fetus. One of the prenatal diagnostic methods is amniocentesis, sampling of embryonic fetuses, CVS, ultrasound, radiographic and direct observation of the fetus.
Amniocentesis: A specialist takes a few cycles of amniotic fluid from the mother at the 16th to 14th week of pregnancy.
CVS testing: A very small sample is taken from the tissue of the placenta attached to the mother’s womb (uterus).
Sonography: One of the most valuable ways to help diagnose some diseases and abnormalities; this method does not pose any risk to the mother or fetus.

Referrals and genetic counseling

Call the Pardis counseling center and call 05138466660 between 2-4pm


Visit the campus counseling center at Second Floor,Ordibehesht Building,Beheshti Ave, Ahmadabad St, Mashhad, Iran


Perform screening and genetic testing

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