What prenatal diagnosis means in the context of the attempted murder of an intractable 1-year-old

What prenatal diagnosis means in the case of the attempted murder of an intractable 1-year-old

What are hereditary diseases? What if I had a prenatal diagnosis during my pregnancy? What should I do if I cannot undergo it? The following is a detailed explanation of these and other issues.

What is the heritability of the disease? What are the conditions for prenatal diagnosis and what kind of care is available if the patient is not eligible for prenatal diagnosis?

The arrest of a mother in her 40s for the murder of her third son, a one-year-old boy with a genetic incurable disease, attracted a lot of attention. Her first son was a carrier of the same disease, although he had not developed it, and she had lost her second son to the same disease, so she wanted her third son to have a prenatal diagnosis, but was unable to receive one, and she was not prepared for the birth.

 What are hereditary diseases? What if I had a prenatal diagnosis during pregnancy? What if I cannot take it?

 , etc., will be explained in detail below.

What are genes?

First, let's look at what genes are.

Our human body is made up of about 60 trillion cells. Each of these cells contains a nucleus, which in turn contains 46 chromosomes. Half of them are inherited from the father and the other half from the mother.  

The chromosomes are made up of a double-helix structure of DNA, the main body of genetic material, consisting of the bases A (adenine), G (guanine), C (cytosine), and T (thymine), which are arranged in various orders. This order is the "genetic information" that gives rise to human individuality.

Genetics is the process by which a person's constitution, face, and personality are passed from parent to child, and not only appearance but also diseases can be caused by gene or chromosome mutations.

About Genetic Diseases

Genetic disorders are diseases caused by mutations in chromosomes or genes, and are divided into three categories: chromosomal aberrations, single gene diseases, and multifactorial inheritance.

chromosomal abnormality

It is believed to be caused by an excess or deficiency of genes in the entire chromosome or in some chromosomes, such as Down syndrome caused by 21 trisomy (normally two chromosomes are paired (dysomy), but the 21st chromosome has three (trisomy).

single-gene disease

It is caused by a mutation in one gene (a single gene) and can be either a mutation that occurs in the gene of the child's generation or inherited from the parent's generation. There are thousands of different diseases, and because of the genetic abnormality, radical treatment is considered difficult, and some diseases develop in adulthood.

multifactorial genetic disorder

It is implicated in the cause of most diseases, including diabetes and Alzheimer's disease. It is caused by both environmental and genetic influences, and in many cases the onset of the disease can be controlled through prevention.

What can we learn from genetic analysis?

Genes can be inherited not only from parents, but also from grandparents, etc., and can be caused by mutations. The cause is unknown, but it is believed that if a woman has had a baby with a chromosomal abnormality before, the probability of having a baby with the same chromosomal abnormality in the next pregnancy is several to ten times higher than the probability of a woman of the same age giving birth to a baby with the same condition.

Genetic analysis during pregnancy refers to some prenatal diagnostic procedures (such as NIPT and amniotic fluid testing) performed during the first half of pregnancy.

Genetic analysis is a test for congenital anomalies, numerical chromosomal abnormalities, and diseases based on genetic mutations, and is performed during pregnancy to accurately diagnose the condition and diagnosis of a fetus with a possible abnormality.

Therefore, conditions are required for testing, such as either the pregnant woman or her partner being a carrier of the chromosomal abnormality or not having developed the disease but being a carrier, or having a history of birth or pregnancy of a child with the abnormality in the past.

Diagnosis requires a number of steps, including a detailed collection of the individual's entire treatment history, family history, and laboratory data for each organ, as well as diagnosis and follow-up by a professionally trained medical staff. Let's take a look at what is required to receive the diagnosis.

Prenatal Diagnosis

Prenatal diagnosis refers to a series of tests performed during pregnancy. The purpose is to diagnose the fetus and to determine if the pregnancy is present, if the fetus is viable, if it is oriented and positioned correctly, and if the mother is at risk for placenta previa or any other danger to the mother.

It is also possible to examine some congenital diseases (e.g., morphological and chromosomal abnormalities) over the course of growth. NIPT has become a hot topic in recent years, especially because the test can be performed at an early age and the risk of stillbirth or miscarriage is low due to the small amount of blood tested.

To be inspected by a licensed agency

  • Age at birth is 35 years or older
  • Pregnant women whose fetus had a possible chromosomal disease by serum marker test or fetal ultrasound
  • Pregnant women who have previously conceived or delivered a baby with a chromosomal disorder
  • One of the parents has a chromosomal abnormality.

The applicant must meet one of the following conditions

The two choices for the purpose of prenatal diagnosis, other than to be prepared in case of fetal abnormality, were to interrupt the pregnancy or to continue the pregnancy and entrust it to a medical institution after delivery.

What is Fetal Treatment?

This treatment was developed in the 1960s with the development of prenatal diagnosis, and is still available at a limited number of medical institutions in Japan. There are two main types of treatment: medical treatment, in which blood transfusions, fluids, and drugs are administered through the mother, and surgical treatment, in which the fetus is treated directly through a uterine incision or a maternal skin incision. At the present time, the treatment is not available for all diseases, but congenital heart disease, hydrocephalus, and twin-to-twin transfusion syndrome are among the diseases that are being treated.

If the surgery is successful, the pregnancy can continue and the prognosis for the fetus is good.

When prenatal diagnosis is not available?

However, the number of facilities that offer testing for chromosomal abnormalities has been increasing in recent years, but not all medical institutions offer the test, so there are cases where the test itself is not available because there are no facilities nearby or appointments cannot be made, or because the patient is a carrier of a chromosomal abnormality without the disease, or because the patient is not eligible for the test for the diagnosis of chromosomal or genetic abnormalities that are not covered by the test.

In the unlikely event that you are unable to receive this service, you have the option of receiving genetic counseling.


  • People with older pregnancies with increased chromosome disorders
  • Have given birth to a child with a chromosomal or genetic disorder
  • People who are concerned about inheritance to their children because they, their spouse, or their relatives have a genetic disorder.
  • People whose tests indicate a high probability of chromosomal disease.
  • Persons considering genetic prenatal diagnosis for any other reason.

Many people also suffer from uncertainty about where to go for counseling and how to get support. We see future issues in terms of counseling as well, such as actually having received counseling but not being able to talk about or understand what they thought they were talking about.

Since information is now easily accessible through social networking services and personal childcare blogs, I believe that utilizing such information sources when it is not possible to visit the hospital or undergo testing for some reason can be an opportunity to face the disease.


Genetic diseases were once considered incurable, but recent advances in medicine have revealed the causes of many diseases, and the overall number of deaths among pediatric chronic disease patients has decreased, saving the lives of many patients.

Although the support available after childbirth is gradually increasing and society is becoming easier for people with disabilities to live in, I believe that there are many aspects that are not yet well understood by the public.

It is important to spread the system that is easy to understand and receive as soon as possible, and also to face it with correct knowledge and information.