Poland Syndrome is a rare condition that is evident at birth (congenital). Associated features may be extremely variable from case to case. However, it is classically characterized by absence (aplasia) of chest wall muscles on one side of the body (unilateral) and abnormally short, webbed fingers (symbrachydactyly) of the hand on the same side (ipsilateral).
In those with the condition, there is typically unilateral absence of the pectoralis minor and the sternal or breastbone portion of the pectoralis major.
The pectoralis minor is a thin, triangular muscle of the upper chest wall; the pectoralis major is a large, fanlike muscle that covers most of the upper, front part of the chest.
Affected individuals may have variable associated features, such as underdevelopment or absence of one nipple (including the darkened area around the nipple [areola]) and/or patchy absence of hair under the arm (axilla).
In females, there may be underdevelopment or absence (aplasia) of one breast and underlying (subcutaneous) tissues.
In some cases, associated skeletal abnormalities may also be present, such as underdevelopment or absence of upper ribs; elevation of the shoulder blade (Sprengel deformity); and/or shortening of the arm, with underdevelopment of the forearm bones (i.e., ulna and radius).
Poland Syndrome affects males more commonly than females and most frequently involves the right side of the body. The exact cause of the condition is unknown.
Signs & Symptoms
Associated symptoms and findings are extremely variable, including in rare cases in which more than one family member has been affected.
For example, in some reported cases, one sibling has had all major features of the condition, while the other sibling has had only absence of pectoral muscle or hand involvement.
However, as noted above, Poland Syndrome is most commonly characterized by absence of chest wall muscles on one side of the body (unilateral) as well as involvement of the hand on the same side (ipsilateral).
In approximately 75 percent of cases, such abnormalities affect the right side of the body.
In most affected individuals, there is absence of the sternal portion of the pectoralis major as well as absence of the pectoralis minor.
The pectoralis major, a large muscle of the upper chest wall, arises from the breastbone (sternum), the collarbone (clavicle), and cartilages of the second to the sixth ribs; it acts on the joint of the shoulder, functioning to move the arm across the body.
The pectoralis minor is a thin, triangular muscle beneath the pectoralis major. This muscle arises from the third to fifth ribs and functions to rotate the shoulder blade (scapula) and move it forward and down.
In some individuals with Poland Syndrome, there may also be unilateral absence of other regional muscles, such as certain large muscles of the back (latissimus dorsi) and/or a thin muscle of the chest wall that extends from ribs under the arm to the scapula (serratus anterior).
In some cases, associated abnormalities may include underdevelopment or absence of the darkened area around the nipple (areola) and the nipple and/or abnormal patchy hair growth under the arm (axilla).
In addition, in affected females, there may be underdevelopment or absence of the breast and subcutaneous tissues.
Additional, variable bone defects may also be present in some individuals with Poland Syndrome.
These may include underdevelopment or absence of certain upper ribs and the bars of cartilage (costal cartilages) by which the ribs are attached to the sternum.
In addition, in some cases, there may be abnormal elevation and/or underdevelopment of the shoulder blade (scapula), limited movement of the arm on the affected side, and the development of a lump at the base of the neck due to elevation of the scapula (a condition known as Sprengel deformity).
(For more information, please choose “Sprengel” as your search term in the Rare Disease Database.)
As noted above, most individuals with Poland Syndrome also have involvement of the hand on the affected side of the body.
Certain bones of the fingers (phalanges) are underdeveloped or absent, resulting in abnormally short fingers (brachydactyly).
In addition, in most cases, there is webbing (syndactyly) of certain fingers, particularly the index and middle fingers.
In addition, in some cases, affected individuals may have abnormal shortening of the arm, with underdevelopment of the bones on the thumb and pinky sides of the forearm (i.e., radius and ulna).
Is it hereditary?
Exactly why this mini-stroke happens is not known. It has been suggested that there might be some hereditary predisposition toward its occurrence.
Cases have been reported of a mother and daughter, or father and son, with similar manifestations of the syndrome. These cases are rare, however. There also are case studies of twins, one with Poland’s syndrome and one without.
Some experts have also theorized that Poland’s syndrome may be the result of exposure by the mother to toxins before birth, but this is only a theory.
Poland’s syndrome is much more commonly seen in males than in females, and it usually affects the right side of the body.
This data suggests that whatever is happening is not completely random, but just why it happens is not yet understood.
The rarity of the condition makes it difficult to study. Most doctors have never encountered a case, and many are unaware of its existence. My own pediatrician brushed it off, saying, “No one is symmetrical.”
Can it be corrected?
Some cases of Poland’s syndrome are more severe than others. The pectoralis major muscle on one side of the body is always at least partially missing, and the hand and fingers on the same side are smaller.
Sometimes the arm is only partially developed, or the fingers may be webbed. In females, the breast and nipple may be missing.
Plastic surgery – to separate fingers or to implant muscle tissue, for example – can correct many of these features.
Because the chest wall is lacking muscles, respiratory problems may be present. Chest muscles enable a person to cough and thus rid the lungs of bacteria and irritants.
Some women with Poland’s syndrome may have difficulty nursing a child. Most of the problems with the syndrome are not physical, however.
Self-consciousness about one’s appearance, and learning to live with others’ reactions (well-intentioned and not), are the greatest challenges for an individual with Poland’s syndrome.
According to reports in the medical literature, an overwhelming majority of cases appear to occur randomly for unknown reasons (sporadically) in the absence of a family history.
However, in some very rare cases, familial patterns have been reported, including occurrence of the condition in a parent and child and in siblings born to unaffected parents.
Some researchers suggest that apparently familial cases may result from inherited susceptibility to a certain event or anomaly (such as early interruption of blood flow) that may predispose to the syndrome (see directly below).
Poland Syndrome is sometimes referred to as Poland sequence. A “sequence” (or anomalad) refers to a pattern of malformations derived from a single anomaly.
According to some investigators, the primary defect in Poland Syndrome may be impaired development of a certain artery or other mechanical factors that may result in diminished or interrupted blood flow during early embryonic growth.
The term “Subclavian Artery Supply Disruption Sequence” has been suggested for a group of conditions that may occur due to disruption of blood flow through particular arteries (i.e., subclavian artery, vertebral artery, and/or their branches) at or around the sixth week of embryonic development.
Such conditions include Poland Syndrome, Moebius Syndrome, Klippel-Feil Syndrome, and Sprengel deformity. The specific pattern of defects that results is thought to depend on the particular site and degree of the diminished blood flow.
(For further information on Moebius Syndrome, see the “Related Disorders” section below. For more on Klippel-Feil Syndrome and Sprengel deformity, choose “Klippel” or “Sprengel” as your search term in the Rare Disease Database.)
Poland Syndrome was named for the investigator (Poland A) who initially described the condition in 1841. According to reports in the medical literature, Poland Syndrome appears to be three times as common in males as females.
Estimates of its incidence have ranged from approximately one in 10,000 to one in 100,000 individuals. (Incidence refers to the number of new cases in a particular period.)
As noted above, Poland Syndrome affects the right side of the body in approximately 75 percent of cases.
In 1998, investigators reported what was thought to be the first known case in which both sides of the body have been affected (bilateral).
Researchers described a young girl with bilateral absence of pectoralis muscle, symmetric chest wall deformity, and bilateral hand involvement.
Symptoms of the following disorders may be similar to those of Poland Syndrome. Comparisons may be useful for a differential diagnosis:
Several investigators have reported cases in which the features of Poland Syndrome occur in association with Moebius Syndrome.
Known as “Poland-Moebius Syndrome,” such cases are characterized by facial paralysis due to impairment of the sixth and seventh cranial nerves (i.e., Moebius Syndrome) associated with the chest wall defects and/or hand malformations (symbrachydactyly) typically seen in Poland Syndrome.
Moebius Syndrome may be characterized by a “masklike”, expressionless face; inability to conduct certain eye movements; drooping of the upper eyelids (ptosis); underdevelopment and/or limited mobility of the tongue; poor sucking and swallowing; and speech impairment.
Additional features may include a deformity in which the foot is twisted out of shape or position (clubfoot); various other limb defects; mild mental retardation; and/or other abnormalities. Moebius Syndrome typically appears to occur randomly for unknown reasons (sporadically).
As mentioned above (see “Causes”), some investigators suggest that the condition may result from early disruption of blood flow through particular arteries during embryonic development (i.e., Subclavian Artery Supply Disruption Sequence).
(For more information on this condition, choose “Moebius” as your search term in the Rare Disease Database.)
Oromandibular-Limb Hypogenesis Syndromes is a term sometimes used to describe a group of rare conditions characterized by underdevelopment (hypogenesis) of the mouth and jaw (oromandibular) areas; parts of the embryo that eventually develop into the arms, legs, hands, and feet (the limb buds); and possibly other areas in the developing embryo.
This “community” of so-called face-limb malformation syndromes includes Moebius Syndrome, Charlie M Syndrome (see below), Hanhart Syndrome, and others.
(For more on Hanhart Syndrome, use “Hanhart” as your search term in the Rare Disease Database.) Such conditions typically appear to occur randomly for unknown reasons (sporadically) and may be characterized by extremely variable clinical features.
Some researchers believe that these are overlapping syndromes or disease variants representing a spectrum of malformations caused by environmental and/or other factors.
As noted earlier, some experts suggest that certain Oromandibular-Limb Hypogenesis Syndromes, such as Moebius Syndrome, may be due to early disruption of blood flow in certain arteries due to various mechanical factors (i.e., Subclavian Artery Supply Disruption Sequence).
Charlie M Syndrome is a rare condition characterized by certain distinctive facial and limb malformations. According to reports in the medical literature, there may be disagreement differentiating between Charlie M Syndrome and various other face-limb malformation syndromes.
The syndrome is characterized by widely spaced eyes (ocular hypertelorism); a broad nose and small mouth; incomplete closure of the roof of the mouth (cleft palate); an abnormally small jaw (micrognathia); facial nerve paralysis in some cases; absent or cone-shaped front teeth (incisors); and variable, asymmetric abnormalities of the fingers and toes.
The condition typically appears to occur randomly for unknown reasons.
A number of other conditions may be characterized by certain chest wall defects, hand malformations, and/or other findings similar to those associated with Poland Syndrome.
(For further information on such disorders, use the exact disease name in question as your search term in the Rare Disease Database.)
The diagnosis of Poland Syndrome is usually made at birth based upon characteristic physical findings, a thorough clinical evaluation, and a variety of specialized tests.
Such tests may include advanced imaging techniques, such as a CT scan that can determine the extent to which the muscles may be affected.
During CT scanning, a computer and X-rays are used to create a film showing cross-sectional images particular organs or structures within the body.
X-ray studies may be used to help identify and characterize specific abnormalities in the hands, forearms, ribs, and/or shoulder blades.
The treatment of Poland Syndrome is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists.
Plastic surgery may be performed to rebuild the chest wall and to graft ribs into their proper places. In females, plastic surgery may also be performed to construct a breast mound. In some cases, surgery may also be performed to help correct skeletal abnormalities affecting other areas of the body such as the hands.
Physical therapy may also be prescribed to help improve any limitations of motion.
Genetic counseling will be of benefit for affected individuals and their families. Other treatment for this disorder is symptomatic and supportive.
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