Beta thalassemias (β thalassemias) are a group of inherited blood disorders. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals. Global annual incidence is estimated at one in 100,000. Beta thalassemias occur due to malfunctions in the hemoglobin subunit beta or HBB. The severity of the disease depends on the nature of the mutation.HBB blockage over time leads to decreased beta-chain synthesis. The bodys inability to construct new beta-chains leads to the underproduction of HbA (adult hemoglobin). Reductions in HbA available overall to fill the red blood cells in turn leads to microcytic anemia. Microcytic anemia ultimately develops in respect to inadequate HBB protein for sufficient red blood cell functioning. Due to this factor, the patient may require blood transfusions to make up for the blockage in the beta-chains. Repeated blood transfusions cause severe problems associated with iron overload. Signs and symptoms
Three main forms have been described: thalassemia minor, thalassemia intermedia, and thalassemia major which vary from asymptomatic or mild symptoms to severe anemia requiring lifelong transfusions. Individuals with beta thalassemia major (those who are homozygous for thalassemia mutations, or inheriting 2 mutations) usually present within the first two years of life with symptomatic severe anemia, poor growth, and skeletal abnormalities. Untreated thalassemia major eventually leads to death, usually by heart failure; therefore, prenatal screening is very important.
Ross syndrome consists of Adies syndrome (myotonic pupils and absent deep tendon reflexes) plus segmental anhidrosis (typically associated with compensatory hyperhidrosis).It was characterized in 1958 by A.T. Ross.By 1992, eighteen cases had been documented.Signs and Symptoms
Initial manifestations often include an abnormal segmental sweating response (described as hyperhidrosis or anhidrosis in some patients) and a tonic pupil. Other commonly reported symptoms included fatigue, chronic cough, and increased urinary frequency.Prognosis
Ross syndrome is a non life-threatening benign condition but delay in diagnosis can result in slow progression of autonomic symptoms. Epidemiology
Ross Syndrome is a progressive autonomic dysfunction that can occur in any age, ethnicity, or gender. The average age of diagnosis for Ross syndrome is 36 years and affects more females than males. See also
Hypohidrosis
List of cutaneous conditions

References


== External links ==