What Is Phocomelia?: Causes and Symptoms

Phocomelia refers to short upper and lower limbs due to birth defects. Having four affected limbs is known as tetraphocomelia. There is a lack of bone development or missing tissue in the affected limbs. It is possible to have limbs growing directly from the trunk in some cases of phocomelia.

A rare defect, phocomelia affects only a small percentage of people. The situation wasn’t always this way, though. Thalidomide, a drug prescribed for anxiety and morning sickness, was recalled for being dangerous during pregnancy in the 1960s.

The discovery resulted in over 10,000 children being born with defects around the world, of which phocomelia was the most prominent. A higher number of miscarriages were reported in the 1960s as well.

In underdeveloped countries where thalidomide is still used as a treatment for leprosy, it may still increase the risk of phocomelia even though it is strictly regulated. Every 100,000 live births, 0.62 are reported to have phocomelia.

Symptoms of Phocomelia

The severity of phocomelia varies. Symptoms of the condition include: [1]

Almost normal hands and feet
Direct attachment of the hand or foot to the trunk
Misaligned or absent bones in the hand and leg, including a bowed hand and an underdeveloped tibia or femur.

may result in phocomelia, a condition that brings about cleft palates, cleft lips, and small noses since the body lack bone structure. [2]

There is also a risk of damage to the shoulders, hips, eyes, and ears from this medication. Lower spinal column vertebrae may fuse or show irregular spacing. There is also the possibility of harm to internal organs, nerves, and the central nervous system (CNS) in the event of thalidomide-induced phocomelia.

Types of Phocomelia

The main types of phocomelia are complete, proximal, and distal.

Complete Phocomelia: Missing limbs refer to missing arms and forearms. Normally, this form of phocomelia is characterized by the attachment of the hand to the base of the trunk.

Proximal Phocomelia: A thigh or arm is missing in this case. Forearms are attached to trunks.

Distal Phocomelia: There is an absence of the legs and forearm in this case. Hands are attached to humeri, not femurs.

Causes of Phocomelia

Genetic inheritance may be to blame for phocomelia, even though its exact cause is uncertain [3]. As a side-effect of thalidomide exposure, it is more common in pregnant women.

There is evidence that thalidomide inhibits inflammation and modulates immunity. Moreover, it might prevent blood cells from forming.

The effectiveness of thalidomide in preventing new blood vessels from forming in the limb has been shown via animal experiments. In limb tissue, it may also cause cell death and promote free radical production.

Taking thalidomide can cause limb buds to grow away from where they are supposed to attach. This is accomplished by blocking or reducing growth factors when a limb is being formed. Furthermore, that can also cause proximal tissue to be removed, preventing the formation of the limb properly. There are also several other locations in the body, such as the torso, where the fingers are affected, or the femur, where the legs are affected. Phocomelia can result from this.

Phocomelia and Related Conditions

The following options may be involved in the diagnosis of phocomelia: [4]

Sporadic Phocomelia: A recessive trait determines the inheritance of phocomelia, a rare genetic disorder. It is also possible that this condition arises spontaneously.
Roberts Syndrome: The bone malformations make this disorder easy to identify. Several factors can lead to an excessive extension of the hands and feet, which may result in phocomelia.
Holt-Hormam Syndrome: The arm, hand, and shoulder are affected by this condition (also known as a trio-digital syndrome). Heart damage may occur in certain cases as well. Typically, this condition results in irregular development of at least one wrist bone. There is an autosomal dominant disorder called Holt-Hormam syndrome.
DK Phocomelia Syndrome: There is nothing common about this disorder. The only distinct characteristics of this disorder are shortened or absent arms, an encephalocele or sac-like projection of the brain, and the membranes covering the brain. Additionally, it can result in abnormalities in the brain and urogenital system, as well as insufficient platelets needed for blood clotting. [5]
Schnitzel-Type Phocomelia: In addition to Al-Awadi-Raas-Rothschild syndrome, this might also be known as Haras Syndrome. In addition to having skeletal abnormalities, it is characterized by the absence of the fibula (the lower part of the leg) or a poorly developed pelvis from birth. Also, the genitalia may be different. There may be no uterus in female subjects, while undescended testes may be found in males. [6]
CHILD Syndrome: Associated with ichthyosiform erythroderma and limb defects, it is also called congenital hemidysplasia. A mutation of the gene NSDHL, which is essential for cholesterol synthesis, results in this condition. Inflammation of the skin is characterized by an itchy and red appearance, typically covered with flaky scales. In addition, it can involve an underdeveloped limb or an absence of one. Children with CHILD syndrome experience most of these symptoms on one side of the body, but can also suffer organ damage. [7]

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Phocomelia management

The first step to treating this condition is having a medical professional perform a physical examination of the insides of the body to exclude any abnormalities and resolve them as soon as possible. Pediatricians should perform this procedure. [8]

A prosthetic limb may be recommended to compensate for a missing limb or to add length. However, many people can function independently without it.

Parents, caregivers, and individuals with phocomelia may also be encouraged to seek professional therapy to provide for the unique requirements of a child with phocomelia. If you are raising a child with a differing ability, it may prove useful psychologically and emotionally.

A Word From Kids Rush

There are a few rare conditions that affect the limbs, such as phocomelia. A person with this condition will face numerous challenges over the course of their lifetime, no matter what the cause. Seeking therapy can provide your child with the information and emotional support necessary to cope with their condition, as well as the care they need.

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