Cataracts can be either a cortical cataract with a blue dot appearance, or a posterior subcapsular cataract. Other organs affected include the heart, lungs, gastrointestinal tract, skin, and brain. Insulin resistance can also occur. Signs and symptoms vary considerably by severity, unusual phenotype, and form (DM1/DM2). DM1 and DM2 differ in regards to the muscles they affect, age of onset, severity of disease, and extramuscular manifestations. DM1
DM1 usually begins in the muscles of the hands, feet, neck, or face. One manifestation of facial weakness is drooping of the eyelid (ptosis). It slowly progresses to involve other muscle groups, including the heart. Myotonia tends to be more prominent in DM1 compared to DM2. Other DM1 manifestations include problems with executive function (e.g., organization, concentration, word-finding) and hypersomnia. Abnormalities in the electrical activity of the heart are common in DM1, manifesting as arrhythmias or conduction blocks. Sometimes, dilated cardiomyopathy occurs. Symptoms onset any time from birth to adulthood. The earlier the disease onset, the greater the variety of possible signs and symptoms. Thus, various diagnostic classifications based on the age of onset/severity of the disease have been proposed, although DM1 manifestations likely lie on a continuum. Congenital DM1
When DM1 onsets at birth, it is called congenital DM1. Manifestations that can be present at birth include hypotonia, respiratory failure, feeding difficulty, and club foot (talipes equinovarus), any of which tend to resolve over several years. During childhood, intellectual impairment, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorders (ASD) can result.
Antithrombin III deficiency (abbreviated ATIII deficiency) is a deficiency of antithrombin III. This deficiency may be inherited or acquired. It is a rare hereditary disorder that generally comes to light when a patient suffers recurrent venous thrombosis and pulmonary embolism, and repetitive intrauterine fetal death (IUFD). Hereditary antithrombin deficiency results in a state of increased coagulation which may lead to venous thrombosis. Inheritance is usually autosomal dominant, though a few recessive cases have been noted. The disorder was first described by Egeberg in 1965. The causes of acquired antithrombin deficiency are easier to find than the hereditary deficiency.The prevalence of antithrombin deficiency is estimated at ~0.02 to 0.2% of the general population, and 1-5% of patients with venous thromboembolism. There is an elevated risk of thrombosis, whereby 50% patients with AT deficiency were found to have venous thromboembolism by age 50. Cause
Diagnosis
A clinical suspicion for antithrombin deficiency can be made in patients with: 1. recurrent venous thromboembolic disease, 2. childhood thrombosis, 3. thrombosis in pregnancy. Testing for antithrombin activity can confirm deficiency if the levels are less than 70%. Deficiency can result from genetic predisposition or from acquired causes such as: acute thrombosis, disseminated intravascular coagulopathy, liver disease, nephrotic syndrome, asparaginase deficiency, oral contraception/estrogens. Genetic testing for abnormalities of the SERPINC1 gene can be done to evaluate further. Management
In patients with antithrombin deficiency, they may develop resistance to unfractionated heparin, especially with continuous infusions. If large quantities of unfractionated heparin are required e.g. greater than 35000 units per day, this would point towards resistance.