What Is Hereditary Lymphedema Type 1A?
Hereditary lymphedema type 1A is a disorder that occurs at the time of birth or develops at the age of two. Milroy disease is a disorder that impacts the regular role of the lymphatic system. The lymphatic system helps in the production and transportation of fluids throughout the body. The lymphatic system helps in boosting immunity. Lymphedema occurs due to impairment in the transportation of fluids along with the proliferation of lymph fluid. This disorder mainly affects the lower legs at the time of birth or during infancy.
What Are the Other Names for Hereditary Lymphedema Type 1A?
Hereditary lymphedema type 1A is also known as
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Primary lymphedema.
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Milroy disease.
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Congenital familial lymphedema.
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Nonne-Milroy lymphedema.
What Are the Causes of Hereditary Lymphedema Type 1A?
Hereditary lymphedema type 1A occurs due to the mutational changes in the FLT4 gene (Fms-related tyrosine kinase 4). The Fms-related tyrosine kinase 4 gene helps in producing a protein called vascular endothelial growth factor receptor 3 (VEGFR-3). The growth factor vascular endothelial receptor 3 controls the development and maintenance of the lymphatic system. The mutations in the Fms-related tyrosine kinase 4 gene affect the growth, activity, and survival of endothelial cells present in the covering of the lymphatic vessels thus leading to the absence or outgrowth of lymphatic vessels.
What Is the Inheritance of Hereditary Lymphedema Type 1A?
Hereditary lymphedema type 1A is based on an autosomal dominant pattern. Autosomal dominance represents that a single copy of an altered gene in each cell is sufficient for the occurrence of the disorder. Most commonly, one affected individual is believed to inherit the mutations from one of the affected parents.
What Are the Signs and Symptoms of Hereditary Lymphedema Type 1A?
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The characteristic feature of hereditary lymphedema type 1A is edema that may be present during birth or momentarily after birth. To know if a fetus is affected during pregnancy, an ultrasound scanning is done. It occurs in rare cases that edema develops in later life in a child.
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The legs are most commonly affected.
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The genitals are also involved.
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Upslanting toenails.
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Papillomatosis (small warty growths on the affected areas).
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Abnormally gigantic or distinguished veins below the knees.
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Urethral abnormalities in the males such as hypospadias and the formation of a fluid-filled sac along the spermatic cord of the scrotum, known as hydrocele.
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Cellulitis or the bacterial infection of the skin and underlying soft tissues.
What Is the Diagnosis of Hereditary Lymphedema Type 1A?
Following are the diagnostic methods used in hereditary lymphedema Type 1A:
Lymphoscintigraphy: It is the standard diagnostic method to rule out hereditary lymphedema type 1A. In lymphoscintigraphy, a tracer, that is, a radioactively labeled colloid substance is injected intradermally through the skin into either the hands or feet. This tracer is transported throughout the body. Lymphoscintigraphy measures the time required for the tracer to be transported from the site of injection to the regional lymph nodes. In the case of hereditary lymphedema type I, the tracer moves slowly or away from the site of injection.
Other Diagnostic Methods: Other specialized imaging techniques are as follows:
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Doppler Ultrasound: It is used to estimate venous conditions like varicose veins and venous blood clots.
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Magnetic Resonance Imaging (MRI): Magnetic resonance imaging is used to detect distinctive features of hereditary lymphedema such as edema, lymphocele (a mass surrounded by lymph fluid), and fibrosis (the formation of fibrous tissue).
What Is the Treatment of Hereditary Lymphedema Type 1A?
Treatment mainly concentrates on the management of edema and prevention of infection by a therapist. The treatment techniques are as follows:
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Fitting compression hosiery and bandaging.
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Massage.
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Supportive shoes.
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Good skincare.
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Complete decongestive therapy (CDT) includes manual lymph drainage in combination with multi-layered compression bandaging, accurate skin care, exercise, and well-fitted compression garments.
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Rehabilitation therapy is necessary for extreme lymphedema which impairs the daily routine activities of the individuals.
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Surgical techniques are used for the treatment of individuals suffering from hereditary lymphedema and microsurgical anastomosis (joining of small lymphatic vessels to other small veins). The surgery is done to create develop a new route to ‘rechannel’ lymphatic fluid flow into the venous system and thus leads to a reduction in swelling.
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For the removal of excess fibrous tissue, surgery is performed but with the help of compression garments.
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Antibiotics are used as a prophylactic measure in case of recurrent infections like cellulitis.
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Antifungal topical medications can also be used for the treatment of an athlete’s foot.
What Are the Preventive Measures To Be Taken?
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Patients suffering from edema should not place their legs in a downward position, at a level lower than the heart as this position increases immobility in the legs.
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Salt intake should be decreased to reduce fluid retention.
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Special care is to be taken to evade wounds in any affected area caused by decreased resistance to infection.
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NSAIDs (non-steroidal anti-inflammatory drugs) such as Ibuprofen, Diclofenac, and calcium channel blockers like Nifedipine, and Nisoldipine should be avoided, as these can exacerbate edema in the legs.
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Diuretics such as Spironolactone are to be added to the diet as a valuable adjunct.
What Is the Differential Diagnosis of Hereditary Lymphedema Type 1A?
Hereditary lymphedema may be associated with several genetic multisystem disorders, such as Klippel-Trénaunay-Weber syndrome, Noonan syndrome, Turner syndrome, and lymphedema-hypoparathyroidism syndrome.
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Noonan Syndrome: Noonan syndrome is a condition known for affecting many parts of the body. The characteristics of the syndrome: distinctive facial features like widely spaced pale blue or green colored eyes, deep philtrum (groove between the nose and mouth), ears that rotate backward, short height, cardiac imperfections, bleeding problems, skeletal defects, high-arched palate, poor teeth alignment, and a small lower jaw (micrognathia).
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Turner Syndrome: It is a chromosomal disorder in which a female infant has only one X chromosome. This syndrome thus, results from a missing or incomplete sex chromosome. The symptoms include short stature, delayed puberty, infertility, heart defects, and certain learning disabilities.
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Klippel-Trenaunay-Weber Syndrome: This condition affects the development of soft tissues, blood vessels, such as skin, muscles, and bones. The disorder has three distinctive characteristics: a red birthmark called a port-wine stain, uncommon overgrowth of soft tissues and bones, and malformations in the veins.
Conclusion:
Hereditary lymphedema is a familial disorder distinguished by lymphedema, generally in the legs, induced by congenital abnormalities in the lymphatic system. Disturbance of the normal drainage of lymph leads to fluid proliferation and hypertrophy of soft tissues. The article reviews the causes, signs, symptoms, diagnostic techniques, and treatment of the disorder.
