Phosphate diabetes is a disease in which the body excretes too much phosphate in the urine. In healthy people, the phosphate is filtered out of the so-called fore urine. The kidneys are primarily responsible for this process. Bone growth is disrupted by the excretion of phosphate, so that phosphate diabetes is similar to rickets.


What is phosphate diabetes?

Phosphate diabetes is sometimes also referred to as vitamin D-resistant rickets or idiopathic Debré de Toni-Fanconi syndrome. The fact that calcium is stored in the human bones is fundamental to understanding the disease. Phosphate plays a key role in this process. See dictionaryforall for Hepatitis in Dictionary.

The disease usually begins in childhood. Basically, phosphate diabetes occurs twice as often in female than in male patients. However, in most cases, the disease is milder in girls. Phosphate diabetes is not contagious to other people. In principle, the disease is a form of rickets caused by hypophosphatemia.


The development of phosphate diabetes has a genetic component. The cause is primarily a mutation in a specific gene that is located on the X chromosome. This also explains why the disease occurs twice as often in women than in men. It is also a dominant mutation.

In this way, just one mutated allele is enough to trigger phosphate diabetes. In principle, however, the exact formation mechanism is still largely unexplored. Some physicians suspect that the relevant gene is involved in the synthesis of membrane proteins. In this way, the retention of phosphate in the organism or in the kidneys is controlled.

Due to the mutation, however, this process is faulty. Basically, calcium and phosphate are connected in human blood. This is also referred to as a calcium phosphate product. If the amount of phosphate decreases, so does calcium. As a result, less calcium is stored in the bones.

However, calcium is an essential building block for the bones to ensure their stability. For this reason, large amounts of calcium are necessary to ensure healthy bone growth in childhood. This is why characteristic deformations of the bones form in the context of phosphate diabetes.

In addition, phosphate diabetes means that no vitamin D is released from the body despite the low concentration of phosphate. This is a common regulatory process in healthy individuals. Insufficient reabsorption of phosphate takes place in the kidneys. Therefore, hypophosphatemia can be detected in the serum of the blood. As a result, the mineralization of the bones is disturbed.

Symptoms, Ailments & Signs

Phosphate diabetes is manifested by various symptoms. In the majority of cases, the symptoms of the disease begin in two-year-old children. The first deformations of the bones are visible in the patients. These appear, for example, in the form of pronounced bowlegs and a genoa.

The gait is often wide-legged and waddling. In addition, the affected children are often too small for their age and may also suffer from impaired tooth development. In some cases, middle ear hearing loss develops because the small bones in the ear canal do not form properly. This is especially the case when there is insufficient treatment. It is also possible that calcium accumulates in the kidneys as a result of phosphate diabetes.

Diagnosis & course of disease

The diagnosis of phosphate diabetes can be made with the help of various tests. First, the medical history is taken between the affected patient or their parents and the doctor. Then the clinical symptoms are subjected to a thorough consideration. Due to the age of the patient at the time of the first manifestation, the suspicion of phosphate diabetes often falls quickly.

Blood tests show reduced concentrations of phosphate in the serum of the blood. At the same time, calcitriol and calcium are present in the usual amounts. X-ray examinations reveal rachitic deformations of the bones.

These are particularly evident in the so-called growth areas on the forearm bones. In advanced stages of the disease, the changes can also be detected in the knee joints. In addition, there are indications of the presence of osteomalacia. It is also important to carry out a thorough differential diagnosis.

It is relevant here that phosphate diabetes shows certain similarities to hypophosphatasia. Therefore, confusion between the two diseases is possible. In addition, the presence of renal osteodystrophy must be checked.


Familial phosphate diabetes leads to complications such as damage to bones or teeth, as well as to kidney dysfunction, if only because of the X-linked hereditary hypophosphatemic rickets. The metabolic disease often leads to joint pain before it is discovered. The joints of the legs twist due to the lack of phosphate. This leads to a waddling gait, knock knees or bow legs.

If the malpositions are particularly pronounced due to phosphate diabetes, they must be corrected orthopedically. If this doesn’t happen, the meanwhile adult faces further complications due to premature wear and tear on the joints. In phosphate diabetes patients, changes in the teeth can also occur as a result of the disturbed phosphate balance.

Fistulas, ulcerated or inflamed root tips can also involve the jawbone. Those affected are threatened with premature tooth loss if the teeth are not treated immediately. Caries and periodontitis are more common in people with phosphate diabetes. Good dental care is essential to avoid such complications.

Further complications can arise in the treatment of phosphate diabetes. The commonly used phosphate and calcitriol therapy shows side effects in at least half of those affected. One of them is increasing renal calcification. If the crystalline deposits in the kidneys are very pronounced, this can lead to high blood pressure and a disrupted filter effect in both kidneys. Further treatment therefore requires close medical supervision.

When should you go to the doctor?

If there are irregularities in the growth and development process of the child, a doctor is needed. Deformations of the physique, peculiarities of the bones as well as bad posture should be discussed with a doctor. A doctor is needed in the case of severe bowlegs or knock knees, a crooked posture and difficulties in moving. Peculiarities of the gait, uncertainties or an increased risk of accidents and falls must be presented to a doctor.

The first irregularities of phosphate diabetes appear in children around two years of age. In the further course, there is an increase in symptoms with a simultaneous decrease in well-being. Disorders of tooth growth or abnormalities in the digestive process must be examined by a doctor. If there is impairment of kidney function, a refusal to drink or pain in the kidney area, a doctor should be consulted immediately. Changes in the complexion or when urinating should be presented to a doctor.

If, in addition to the physical symptoms, there are also emotional or psychological problems, it is also recommended to consult a doctor. In the event of withdrawal behavior, social isolation or apathy, the person concerned needs help. Teariness or abnormal behavior are to be understood as warnings. There is a health impairment that should be clarified and examined. Anxiety, feelings of shame, sleep disorders or loss of appetite are signs of a stress condition that needs to be clarified.

Treatment & Therapy

In principle, phosphate diabetes is treated symptomatically, since it is not possible to eliminate the causes. The focus of therapy is the administration of calcitriol and phosphate. It is important to start drug treatment as early as possible. In this way, damage and deformation of the bones can be avoided to a certain extent. In addition, regular kidney examinations are necessary, as the development of nephrocalcinosis is promoted.

Outlook & Forecast

Phosphate diabetes is a rare special form of rickets. The first symptoms appear from the second year of life. Gait abnormalities, short stature and a conspicuous tooth development disorder occur. It is questionable whether these lead to a differential diagnosis. However, the prognosis of phosphate diabetes depends very much on how early the disease is detected.

With timely treatment, the prospects for the little patients are best. If phosphate diabetes is not treated in time, there is a risk of skeletal deformities and permanent sensorineural hearing loss. The skeletal deformities can only be corrected surgically after the end of bone growth. Until then, a pediatric orthopaedist should be consulted. If inner ear hearing loss already exists, it can usually no longer be corrected. However, there are ways to alleviate them.

However, the treatment of this disorder is complex and must be undertaken with care. In the case of phosphate diabetes, the small patients usually have to be given phosphate and calcitriol. Constant monitoring of calcium excretion via the urine is necessary. Administration of calcitriols in overdoses can result in hypercalcemia with nausea and vomiting. The medication can also lead to nephrocalcinosis. The latter can lead to renal insufficiency. That means years of dialysis. There may be a need to find a donor kidney. Therefore, regular ultrasound examinations are useful.


Measures to prevent phosphate diabetes are not known because the disease is hereditary. Medical examinations must be initiated at the first symptoms of the disease, since starting treatment early improves the prognosis of phosphate diabetes significantly.


In most cases, those affected by phosphate diabetes do not have any special and direct follow-up measures available, so that in the case of this disease, the priority should be a quick diagnosis and subsequent treatment of the disease. As a rule, self-healing cannot occur, although the disease can lead to serious complications if it is not treated.

Therefore, at the very first signs and symptoms of the disease, the patient should contact a doctor. The treatment itself is carried out with the help of various medications, although a complete cure for phosphate diabetes is usually not possible. Patients are therefore dependent on lifelong therapy.

It is always important to take the medication regularly and also to pay attention to the recommended dosage in order to alleviate the symptoms properly and permanently. Regular check-ups by a doctor are also necessary. Possible malformations of the bones can be alleviated by surgical interventions, whereby the person concerned should rest and rest after such an intervention in any case. This disease may reduce the life expectancy of those affected, although it is usually not possible to make a general prediction about the further course.

You can do that yourself

According to the current state of research, phosphate diabetes is genetically determined and cannot be treated causally. There are therefore no self-help measures that have a causal effect. However, the sooner the disease is recognized and adequately treated, the fewer the long-term effects to be expected.

Since congenital phosphate diabetes is already evident in childhood, it is primarily the parents who are called upon to do so. Anyone who comes from a family in which phosphate diabetes has already occurred should be aware of the symptoms and, even if they are healthy themselves, monitor their children for them. If growth retardation or other abnormalities appear, a doctor must be consulted immediately. It is extremely important to point out to the treating physician that there is a family history of phosphate diabetes. Since this disease is a rather rare disorder, there is otherwise a risk that it will be recognized too late. A diagnosis that is too late, however, often causes an abnormal development of the ear canal in the affected small child, which is no longer reversible.

Parents should not leave the treatment of their child to their family doctor alone, but insist that a doctor who already has experience in treating phosphate diabetes is consulted. Those affected receive support in their search for a suitable doctor from the Medical Association. In addition, there has also been a self-help association for a number of years, which advises patients and their relatives.