Monkey fold: causes, symptoms, diagnosis, treatment, correction and doctors advice

What is a monkey fold? This is a special line in the palm of your hand that is found in a small number of people. This feature is not a pathology. But doctors drew attention to the fact that such a groove on the arm is sometimes noted with chromosomal diseases and malformations. In many cases, it is also observed in healthy people. However, if this line is found in a newborn, then special attention should be paid to the health of such a child.

What is this line

Often, doctors and palmists talk about a monkey fold in the palm of your hand. What does this term mean?

We will examine the medical and clinical significance of this definition. In the upper part of a person’s palm, two horizontal lines can be found. This is a three-finger and five-finger grooves. In chirology, they are called the line of the mind and the line of the heart. In most people, these skin folds are located separately and do not overlap. These furrows can be seen in the photo below.

Lines on the palm

In a small percentage of people, these lines merge into one. In this case, a wide groove crosses the palm of a person. This feature is called a monkey fold in the palm of your hand. Such a line exists in anthropoid primates. This is the name of the fold. Otherwise, it is called the Simian line (from the English word Simian - "monkey-like"). A photo of the monkey fold can be seen below.

Monkey fold in the palm

We can say that a person has only one line in his palm instead of three. The term "four-finger groove" is also used. Such a fold on one arm is observed in 4% of people, and on two - in 1%. It is more common in men than in women.

Embryogenesis Disorders

The formation of skin patterns on the palms of a person occurs in the third month of fetal development. It is during this period that an unborn fold of a hand may form in the unborn child.

This feature can be inherited from parents. In this case, it does not indicate any diseases. But often such a transverse groove speaks about violations of embryogenesis. Together with the abnormal formation of skin patterns in the fetus, other deviations can be observed.

Intrauterine development

The Simian line is a kind of anomaly of development. This formation of skin folds in the palm of your hand cannot be considered the norm. If at the same time the unborn child has no other anomalies, then such a skin pattern on the palm does not pose any danger. But often this feature is combined with more dangerous malformations.

Down Syndrome

Monkey fold is found in 40-50% of patients with Down syndrome. Usually this feature is noted on only one hand. Down syndrome refers to congenital chromosomal abnormalities. The disease is characterized by mental retardation of varying degrees. Patients have a characteristic appearance: a flat face, a short skull, slanting eyes.

Child with down syndrome

Other congenital abnormalities

The Simian line is found in most children with Patau syndrome. This is a severe congenital pathology, characterized by multiple malformations. In most cases, children die before the age of 1 year.

A monkey fold on one arm is often observed in patients with Noonan syndrome. Patients have low growth, delayed puberty, heart defects and chest deformities. Intellectual development may remain normal; in some patients, mental development is impaired.

Monkey fold also occurs in men with Klinefelter syndrome. This is a congenital disease in which the boy has an increased number of female X chromosomes. Manifestations of this disease are usually noted in adolescence. The boy has high growth, gynecomastia and puberty disorders.

However, this feature of the furrows in the palm of the hand does not always indicate chromosomal abnormalities. It occurs in 7% of women suffering from congenital abnormalities in the structure of the uterus.

The Symian line is also observed in people with heart defects. In this case, it is somewhat shifted to the upper part of the palm.

Does it always mean illness

Is it possible to diagnose a monkey fold in the palm of your hand? This feature is far from always a sign of a disease. The Symian line can also be found in absolutely healthy people who do not suffer from any pathologies. The transverse groove itself is not a disease, it can only be one of the symptoms of a congenital ailment.

This symptom alone is not enough to diagnose the disease. This feature should be considered only in combination with other manifestations of genetic disorders.


What to do if a newborn has a transverse groove in the palm of his hand? If the child does not have any other abnormalities, then this symptom should not be cause for concern. This does not mean that the baby was born sick. However, doctors recommend a karyotype blood test. This test accurately detects chromosomal abnormalities.

Human chromosomes

A blood test should be taken, since there are mosaic forms of chromosomal abnormalities. They are not always accompanied by pronounced symptoms and changes in the appearance of the newborn. Mosaic disturbances appear only over time. In this case, a transverse groove in the palm of your hand may be the only sign of pathology, and it is advisable to undergo an additional examination. It should be remembered that this feature indicates a 45% probability of having Down syndrome.

If the child has other obvious signs of a genetic abnormality, then the presence or absence of the Simian line is not very important for diagnosis.

If such a fold in the palm of the hand is observed in an adult, then when planning childbirth, he is recommended to visit genetics. Specialist consultation is necessary even if the patient feels absolutely healthy. This is important for the health of his unborn children.


The presence of a transverse groove in the palm of your hand may be just one of the symptoms of chromosomal abnormalities. Therefore, it is necessary to treat the underlying disease.

Most of the genetic abnormalities are not completely cured. Modern medicine cannot affect the composition of chromosomes. However, it is necessary to timely correct the congenital disorders:

  1. With Down syndrome, it is necessary from an early age to develop speech and communication skills of the baby. It is also important to pay attention to the health of the child. Such children often suffer from heart defects, and also have problems with muscles and joints. Therefore, the child should be regularly monitored by a pediatrician.
  2. With Noonan syndrome, a teenager is undergoing hormone replacement therapy. This allows you to accelerate delayed sexual development. At an early age, developmental activities are indicated, since such children may experience mental retardation.
  3. With Klinefelter's syndrome, testosterone preparations are indicated. If the boy or youth has signs of gynecomastia, they undergo plastic surgery.
  4. Patau syndrome is practically not amenable to therapy. This serious disease has an extremely poor prognosis. Medical assistance to a child consists only in constant monitoring of his condition and symptomatic treatment.
Educational activities


The Symian line is most often observed in chromosomal diseases. To date, the prevention of such anomalies has not been developed. However, similar pathologies in the unborn child can be detected using prenatal diagnosis.

Every pregnant woman should be screened. Such an examination allows us to identify chromosomal abnormalities at the stage of fetal development. Screening is especially indicated for patients older than 35 years. After all, children with Down syndrome and other congenital disorders are more often born in women who are of late reproductive age.


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