Case Presentation: We present a 48-year-old Caucasian female with a past medical history of breast cancer, status post-mastectomy, admitted for a month of abnormal uterine bleeding, secondary to fibroids; continued blood loss led to acute kidney injury. Retroperitoneal ultrasound showed multiple cysts of various sizes throughout both kidneys with left renal enlargement consistent with ADPKD; the patient then shared her strong family history of ADPKD. A thorough chart review during her stay revealed a history of beta-thalassemia minor. This was consistent with her anemia that showed a concurrent iron deficiency as well as thalassemia (Hg 4.8, Hct 17.1%, MCV 81.1, RDW 23.9). The patient was treated for uterine bleeding and advised to share her diagnosis of ADPKD with all healthcare providers.
Discussion: Autosomal dominant polycystic kidney disease (ADPKD) has shown to be associated with hemoglobinopathies. Past studies have shown that Hemoglobin C and S, commonly inherited hemoglobin disorders, have an increased risk of ADPKD [1.2]. Alpha-thalassemia has been shown to be inherited with ADPKD in the Caucasian population [3]. ADPKD has been associated with a variety of malignancies including solid tumors and hematologic malignancies as well as hemoglobinopathies [4]. It is generally diagnosed clinically based on patient age, family history and ultrasound imaging demonstrating numerous types of renal cysts of varying sizes [5]. ADPKD displays allelic heterogeneity at its PKD1 (Polycystin 1, 16p13.3) and PKD2 (Polycystin 2, 4q22.1) genes [6]. Beta-thalassemia minor (11p15.4), a carrier condition of heterozygous beta+ or beta0 mutations, often tends to be asymptomatic concomitant with a mild anemia with marked microcytosis [7,8].We present a Caucasian female with ADPKD that tested negative for both HgC and HgS mutations who was found to have beta-thalassemia minor. This is the first case to our knowledge of a patient with beta-thalassemia minor co-inherited with ADPKD.
Conclusions: This case demonstrates a rare genetic co-inheritance between ADPKD and Beta-thalassemia minor; where ADPKD has only been classically associated with alpha-thalassemia and other hemoglobinopathies [3]. Further genetic testing and evaluation of the patient and her family will be necessary to determine any existing consequences or correlations between the two inherited diseases. We suggest providers consider performing a hemoglobin electrophoresis in patients with clinical features of ADPKD or diagnosed ADPKD and unexplained microcytic anemia. One might consider ADPKD in patients with diagnosed beta-thalassemia minor, however routine screening is not currently recommended due to an undetermined frequency of such a co-inheritance.