Analbuminemia is a congenital, autosomal recessive disorder characterized by very low serum levels of albumin. The majority of patients, however, exhibit minimal manifestations such as hypotension, mild fatigue, and edema of the distal lower extremities. Severe hypercholesterolemia as a compensatory mechanism typically seen in the laboratory workup may predispose to an early onset of atherosclerosis and consequent cardiovascular diseases. Genetic testing is necessary to confirm mutations responsible for diminished concentrations of albumin.
Analbuminemia is an extremely rare congenital disease that denotes very low circulating levels of albumin (<1.0 g/L) [1] [2]. As one of the main plasma proteins, involved in oncotic pressure regulation and in the transport of numerous compounds throughout the body, albumin is a highly important molecule for human body functioning [1] [3]. However, virtually all patients develop only minimal symptoms as significant levels of lipoproteins (but also other classes of proteins) are secreted to compensate for albumin loss [1] [4]. Excessive hypercholesterolemia predisposes patients suffering from this rare condition to atherosclerosis and cardiovascular diseases [1] [4]. The main manifestations of analbuminemia are mild fatigue, edema around the ankles, and hypotension [1] [2]. Notable complications that have been described are osteoporosis, development of hypercoagulable disorders, infections of the respiratory tract, intrauterine growth retardation, and fetal death [5]. In fact, some authors claim that the very few cases of analbuminemia described in the literature are due to the underdiagnosis related to very early deaths from this condition [4].
The very rare occurrence of analbuminemia (only 50 cases have been reported in the literature and an incidence rate of < 1 in 1 million individuals was established) and the nonspecific, generally benign symptomatology must not mislead the physician from taking a detailed patient history and conducting a thorough physical examination [1]. A presumptive diagnosis can be made after laboratory studies that confirm profoundly low levels (< 1.0 g/L) of albumin in the serum but with normal liver function (coagulation panel and serum transaminases within physiological limits) and exclusion of albumin loss through the kidneys or the gastrointestinal tract [1] [2] [4] [6] [7]. Since certain molecules are usually bound to albumin at the time of testing (such as calcium and thyroxine), a true diagnosis may be delayed or missed for a significant period of time because of misleading laboratory results [1] [4] [8]. For this reason, more advanced studies, including molecular analysis to detect gene mutations located on chromosome 4, are necessary to solidify the diagnosis [1] [2] [9]. Because the disorder is transferred through an autosomal recessive pattern of inheritance [1] [2] [7], a family history might provide important clues as well, making it a vital constituent of the diagnostic workup.