Associated conditions
Patients with a horseshoe kidney can develop sequelae related to the abnormal anatomy and present with symptoms related to them.The general categories a horseshoe kidney may increase the risk for fall under the following categories:

Kidney obstruction – commonly causes ureteropelvic junction obstruction (UPJ) which is a blockage at the area where the ureter connects to the renal pelvis. This can lead to urinary stasis which can promote infection and stone formation. Kidney infections – associated with vesicoureteral reflux (present in approximately 50% of all patients with renal fusion) which is an abnormal reflux of urine back into the ureters that increases risk of urinary tract infections. Kidney stones – deviant orientation of kidneys combined with slow urine flow and kidney obstruction may increase the risk of developing kidney stones. Treatment is further complicated if patient possesses aberrant skeletal anatomy. It is estimated 36% of patients with horseshoe kidneys will develop kidney stones. Kidney cancer – increased frequency of certain renal cancers such as transitional cell tumors, Wilms tumors, and carcinoid tumors. Heart abnormalities – ventricular septal defect
Neurological abnormalities - encephalocoele, myelomeningocoele, spina bifida
Skeletal abnormalities - kyphosis, scoliosis, hemeivertebra, and micrognathia. Genitourinary abnormalities - septate vagina, bicornuate uterus, hypospadias, undescended testis, adult polycystic kidney disease, and more than two kidneys. Genetic abnormalities - Turner syndrome, Down syndrome, Patau syndrome, Edward syndrome, oro-cranial-digital syndrome

Cause
There have been several proposed factors that may contribute to the development of a horseshoe kidney. Different exposures to the developing fetus such as different teratogens (e.g.
Horseshoe kidney, also known as ren arcuatus (in Latin), renal fusion or super kidney, is a congenital disorder affecting about 1 in 500 people that is more common in men, often asymptomatic, and usually diagnosed incidentally. In this disorder, the patients kidneys fuse to form a horseshoe-shape during development in the womb. The fused part is the isthmus of the horseshoe kidney. The abnormal anatomy can affect kidney drainage resulting in increased frequency of kidney stones and urinary tract infections as well as increase risk of certain renal cancers.Fusion abnormalities of the kidney can be categorized into two groups: horseshoe kidney and crossed fused ectopia. The horseshoe kidney is the most common renal fusion anomaly. Signs and symptoms
Although often asymptomatic, the most common presenting symptom of patients with a horseshoe kidney is abdominal or flank pain. However, presentation is often non-specific. Approximately a third of patients with horseshoe kidneys remain asymptomatic throughout their entire life with over 50% of patients having no medical issues related to their renal fusion when followed for a 25-year period. As a result, it is estimated that approximately 25% of patients with horseshoe kidneys are diagnosed incidentally with ultrasound or CT imaging.