Overview

Frohlich syndrome is a rare syndrome that can occur in children. Some symptoms include obesity, delay in puberty and genital development. This is not inherited but is acquired; it is commonly caused by tumours in the hypothalamus.¹ The hypothalamus is an area in the brain that regulates sleep and body temperature. It is also linked to the pituitary gland, which is important for growth, metabolism and body development; therefore, tumours in the hypothalamus can indirectly cause the symptoms present in Frohlich syndrome.²

Causes

Although tumours are the most common cause of Frohlich syndrome, as they are in an area of the hypothalamus that causes it to be unable to stimulate the pituitary gland, which is required for normal puberty and regulation of appetite. The tumour is usually a craniopharyngioma, which is a slow-growing tumour that can cause problems with vision and the endocrine system. Frohlich syndrome can also be caused by inflammation, for example, by tuberculosis or inflammation of the brain, like encephalitis. This results in damage to the area of the hypothalamus near where tumours would be present.³

Symptoms

There is a wide range of symptoms associated with Frohlich syndrome; however, some of the symptoms include:

• Increased or excessive eating, which can result in obesity
• Small testes
• Delay in the onset of puberty
• Delay in physical growth
• Delay in secondary sexual characteristics
• Children tend to be short

Less common symptoms of Frohlich syndrome, which may be caused by a tumour:

•  Poor vision due to optic nerve damage
•  Low body temperature
•  Delicate skin
•  Infundibulo-tuberal syndrome which can result in diabetes and drowsiness

Diagnosis

Symptoms of Frohlich syndrome can be similar to other disorders, such as Prader-Willi syndrome, which has overlapping symptoms of excessive appetite, short stature and small genitals. Borjeson syndrome also has overlapping symptoms such as obesity, seizures and genital development. Therefore, it is important to be examined and diagnosed by a professional if you suspect that your child has these symptoms.

A specialist will conduct laboratory analysis to determine whether your child has Frohlich syndrome by examining the pituitary hormones, which would be low due to damage or tumours in the hypothalamus. These laboratory tests include blood tests to examine FSH, LH and GH levels. Doctors may also include CT or MRI scans of the brain to determine whether there are tumours, and additional tests may be performed to ensure it is Frohlich syndrome and not any of the other syndromes that have overlapping symptoms.⁴ 

Treatment

If a tumour is the cause of the symptoms, then it would be advisable to remove the tumour surgically if possible or through chemotherapy or radiotherapy. However, if the Frohlich syndromes are caused by lesions, then hormone replacement therapy may be used to replace the hormones that are low because of the damage. For people assigned male at birth, this may be human chorionic gonadotropin to reach puberty, and also testosterone. For people assigned female at birth, it may be oestrogen. However, managing excessive appetite may be more difficult and individualised; some treatments may include GLP1 analogues.

Conclusion

Frolich syndrome is a rare disorder that causes a wide range of symptoms but can be treated if correctly diagnosed. Therefore, it is important that you go to a specialist if you suspect that your child may have Frolich syndrome, especially as the symptoms are quite general and can overlap with several other disorders.