Signs and Symptoms-Alström Syndrome

Alström syndrome may potentially affect several different organ systems of the body. The specific symptoms associated with Alström syndrome, their severity and their rate of progression vary greatly from one person to another, even among members of the same family. It is important to note that affected individuals will not have all of the symptoms discussed below and individual cases may be dramatically different. Some symptoms may present in the first weeks of life, others symptoms may not develop until adolescence or early adulthood.

Retinal degeneration: This is often the first feature of Alström Syndrome that is noticed. Individuals with Alström syndrome often develop vision abnormalities, specifically cone-rod dystrophy, between birth and 15 months of age. Cone-rod dystrophy is a form of retinal dysfunction. In affected individuals, the cells in the retina (cones and rods [photoreceptors]) that convert light into nerve impulses gradually deteriorate (cone-rod dystrophy), causing vision loss. In addition to visual impairment, affected individuals may develop severe sensitivity of the eyes to light (photophobia) and rapid, involuntary eye movements (nystagmus). The progression and degree of visual impairment varies among affected individuals. Some individuals may also develop clouding of the lenses of the eyes (cataracts). In most cases, vision becomes progressively worse through the first and second decade and may result in blindness by the mid-teens. Some individual are able to read large print into their third decade.

Hearing loss: This is usually noticed before the age of 10. The severity of hearing loss in Alström Syndrome varies considerably. Hearing is usually normal at birth, but sometime during the first decade of life, progressive sensorineural hearing loss may affect both ears (bilateral) in approximately 70% of patients. Sensorineural hearing loss is caused by an impaired ability of the auditory nerves to transmit sensory input to the brain. Hearing loss may be mild to moderate in degree or may progress to severe or moderately severe by the end of the first or second decade of life. Chronic infection or inflammation of the middle ear (otitis media) may also occur. Some individuals may develop the accumulation of thick, sticky fluid behind the eardrum (glue ear). Long-standing glue ear can cause conductive hearing loss in some cases. Conductive hearing loss is cause by the blockage of sound waves.

While vision and hearing are affected in individuals with Alström syndrome, intelligence is usually unaffected. Some infants and children may experience delays in reaching developmental milestones such as crawling or walking. Some children may have delays in developing certain language skills or develop learning disabilities.

Obesity: Children and young people with Alstrom Syndrome have a lower energy requirement and generally are less active compared with their peer group; as a result they have a higher risk of obesity. This weight gain tends to be less severe in later life Type 2 diabetes. Birth weight is normal in infants with Alström syndrome, but excessive eating beyond the normal need to satisfy hunger (hyperphagia) and rapid weight gain may occur during the first year of life. Some affected children develop childhood truncal obesity, a condition in which fat is disproportionately distributed on the abdomen and chest rather than the arms and legs. As affected individuals age, some may see their body weight fall, often regaining normal or slightly above-average weight for their size.

In childhood, height is typically normal or above normal. As the child grows into adolescence and adulthood, growth slows and final adult height is below the 50th percentile.

Cardiomyopathy: More than 60 percent of children with Alström syndrome develop a condition known as dilated cardiomyopathy, in which weakening of the myocardium–the heart muscle forming the walls of the heart chambers–leads to enlargement (dilatation) of the heart’s lower chambers (ventricles). Dilated cardiomyopathy may not be associated with any symptoms initially, but eventually leads to weakening of the heart’s pumping action, which impairs the circulation of blood through the lungs and the rest of the body resulting in fluid buildup in the heart, lung and various body tissues (congestive heart failure).

Associated symptoms and findings may depend upon the degree of heart failure. For example, in some infants, signs of heart failure may include feeding difficulties and poor weight gain, irritability, excessive sweating; labored, rapid breathing (tachypnea); bluish discoloration of the skin and mucous membranes due to abnormally low levels of circulating oxygen (cyanosis), among other findings. Children with heart failure may develop fatigue; shortness of breath (dyspnea), coughing, lack of appetite (anorexia); or abdominal pain.

Dilated cardiomyopathy can develop during infancy or in early adulthood.

Type 2 diabetes: In young adulthood, children with Alström Syndrome tend to become resistant to insulin, and can go on to develop Type 2 diabetes. High blood fat levels are also common in people with insulin resistance. Children as young as five have developed type 2 diabetes mellitus. In this form of diabetes, the pancreas produces insulin but the body becomes resistant to its effects, leading to insufficient absorption of glucose and abnormally increased glucose levels in the blood (hyperglycemia) and urine. As a result, there may be a gradual onset of certain symptoms, including excessive urination (polyuria) and increased thirst (polydipsia), and the development of particular complications without appropriate treatment.

Skin disorder: Individuals with Alström syndrome often develop a condition known as acanthosis nigricans, a skin disorder characterized by abnormally increased coloration (hyperpigmentation) and “velvety” thickening (hyperkeratosis) of the skin, particularly of skin fold regions, such as of the neck and groin and under the arms (axillae). Acanthosis nigricans may be a skin manifestation of insulin resistance.

Urological abnormalities: Some individuals with Alström syndrome develop various urological abnormalities. As with other symptoms, the severity of urological abnormalities can vary greatly. Affected individuals may be unable to coordinate the muscles of the bladder and the tube that carries urine from the bladder out of the body (urethral dysynergia). Additional abnormalities include difficulty beginning urination, reduced flow, increased time between urinating, inability to control bladder movements (incontinence), and urinary retention. Urinary abnormalities may alternate between underactivity and over activity of the bladder. Many individuals with Alström syndrome also have recurrent urinary tract infections.

Renal (kidney) failure: Affected individuals often experience slowly progressive dysfunction of the kidneys. Onset of kidney dysfunction may be during adolescence or adulthood. In many individuals, early kidney dysfunction may not cause symptoms (asymptomatic). Two common signs of kidney disease are excessive urination (polyuria) and excessive thirst (polydipsia). Eventually, symptoms including swelling of the ankles or a general feeling of ill health (malaise) may develop. Kidney dysfunction may progressively worsen eventually causing end stage renal failure, which can occur as early as the mid or late teen-aged years.

Pulmonary problems: Some individuals may develop breathing (respiratory) or lung (pulmonary) problems such as chronic respiratory infections beginning early during childhood. These chronic infections can contribute to the development of asthma, chronic inflammation of the sinuses (sinusitis), a dry cough, and repeated episodes of inflammation of the bronchial tubes (bronchitis) or pneumonia. More serious pulmonary complications can occur including high blood pressure of the main artery of the lungs (pulmonary hypertension), chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome, and emphysema.

Liver diseases: The liver may be involved in some cases resulting in abnormal enlargement of the liver (hepatomegaly). The severity of liver involvement can range from elevated liver enzymes, which are common in childhood to fatty liver disease (steatohepatitis). Steatohepatitis is characterized by the accumulation of fatty material in the liver and is often associated with diabetes or obesity. Liver (hepatic) dysfunction may occur and can progress to cause scarring (cirrhosis) within the liver, high blood pressure of the main vein of the liver (portal hypertension), abnormal enlargement of the spleen (splenomegaly), the abnormal accumulation of fluid in the abdominal cavity (ascites) and, eventually, liver failure by the second or third decade.

Some (but not all) of the following additional symptoms may be present in patients with Alström syndrome:

Some males with Alström syndrome may experience diminished hormone production by the testes (hypogonadotrophic hypogonadism). The onset of puberty may be delayed. Some affected males may develop abnormally enlarged breasts (gynecomastia).

Hypogonadism also occurs in affected females, but may not be apparent until puberty. Affected females may develop polycystic ovarian syndrome (PCOS). PCOS can result in irregular menstrual periods or a lack of menstruation, oily skin that is prone to acne, cysts on the ovaries and mild hirsutism (a male pattern of hair growth). Hair may develop on the upper lip and chin. PCOS may occur as a symptom of insulin resistance. In some cases, females enter puberty early (before the age of 8), a condition called precocious puberty.

Additional symptoms may be associated with Alström syndrome including low levels of growth hormone, which may result in short stature in adulthood; high blood pressure (hypertension), abnormally decreased activity of the thyroid gland and underproduction of thyroid hormones (hypothyroidism), advanced bone age; patchy areas of hair loss (alopecia); gastroesophageal reflux; pain in the middle of the abdomen just below the sternum (epigastric pain); and abnormal side-to-side (scoliosis) or front-to-back (kyphosis) curvature of the spine.


Causes of Alström Syndrome

Diagnosis of Alström Syndrome

Treating Alström Syndrome



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