Two unrelated patients, both female, were reported in 2015.
There is general delay in motor, physical, and mental development. Other signs such as swelling of the lower limbs (lymphedema) may be apparent as early as one year of age. Platelets that circulate in the blood (important structures necessary for blood clotting) are greatly reduced in number and often enlarged. These features are likely present throughout life. There may also be fluid on the heart (pericardial effusion), in the abdomen (ascites), and around the lungs (hydrothorax). Hearing loss and heart malformations may be present. Intellectual disabilities may be severe.
Facial features consist of a flat midface and droopy eyelids. Vision is poor and at least one individual has been found to have abnormal development of the retina. Strabismus (misalignment of the eyes), and nystagmus (jerky movements of the eyes) are present. An unusual feature is the outward turning of the lower eyelids (lid eversion).
Two reported individuals have had mutations in the same gene even though they were unrelated. This suggests this is an autosomal dominant condition inherited in a vertical pattern. Affected individuals with this mutation can expect that half of their children will inherit the mutation but the developmental delay features likely preclude reproduction.
Detection at birth is unlikely but features such as delayed mental and physical development, swelling of the lower limbs, and the platelet abnormalities could be used within the first year of life to make the diagnosis. A multidisciplinary team of pediatricians, hematologists, and neurologists would likely need to collaborate.
Nothing is known about treatment and prognosis.