Definition

Prader-Willi syndrome is a complicated hereditary condition that impacts multiple systems. The prevalence of this condition is estimated to be 1 in 10,000 to 30,000 individuals globally.

Causes

Prader-Willi syndrome results from the impairment of gene function within chromosomal 15. Typically, an individual inherits one copy of this chromosome from both parents. The absence of a particular section of chromosome 15 inherited from the father, which affects each cell, is the root cause of about 70% of Prader-Willi syndrome cases. Important genes are absent in people with these chromosomal abnormalities. Other, less prevalent chromosomal abnormalities can cause genes to become inactive, leading to Prader-Willi syndrome.

This condition induces multiple disorders and is hypothesized to impact the hypothalamus, a cerebral region responsible for hormone production, appetite, and growth regulation. This explains certain characteristic features of Prader-Willi syndrome, including persistent appetite and stunted growth.

The absence of the OCA2 gene in specific individuals with Prader-Willi syndrome contributes to the manifestation of symptoms, including extremely pale skin and light hair. A segment of chromosome 15 contains the OCA2 gene, which is frequently absent in individuals with Prader-Willi syndrome. The proteins encoded by these genes regulate eye, hair, and skin pigmentation.

Risk Factor

Prader-Willi syndrome may affect males and females of any ethnic origin, regardless of their heritage. Prader-Willi syndrome is often not inherited, particularly from deleting a gene located on chromosome 15. Although uncommon, Prader-Willi syndrome-causing mutations can occasionally be inherited.

These genetic modifications develop randomly throughout early embryonic development or the formation of reproductive cells (ovum and sperm cells). In most cases, individuals diagnosed with Prader-Willi syndrome do not have a familial predisposition to the disorder. The probability of a pair of parents having more than one child diagnosed with Prader-Willi syndrome is exceedingly low.

Symptoms

Physical, psychological, and behavioral developmental disorders can affect Prader-Willi syndrome patients. Signs and symptoms include:

• Muscle weakness

Muscle weakness is typically observed in the initial postnatal period. This condition is known medically as hypotonia. The following characterizes hypotonia:

• • Limited range of motion
  • Feeble cries
  • Limited motor responses
  • Inadequate sucking ability, resulting in potential challenges with nursing, inadequate weight gain until the age of one, and potential dependence on a feeding tube

• Sexual development disorder

Male infants may exhibit atypical penile sizes, which are smaller than typical. Additionally, one or both testicles may remain in the abdominal cavity, failing to descend into the scrotum (a condition known as undescended testicles). Infant females are equally susceptible to abnormalities affecting the development of their reproductive organs. Individuals diagnosed with Prader-Willi syndrome exhibit a delayed onset of puberty and may not completely reach maturity.

• • Men continue to have high-pitched vocal tones and no facial or body hair
  • Women do not begin menstruating until they reach the age of 30, and their breasts do not reach full development. If it happens, menstruation is typically characterized by irregularity and a minimal flow

The reproductive possibilities of individuals with Prader-Willi syndrome, whether male or female, remain uncertain. Typically, infertility occurs due to abnormal development of the testicles and ovaries. Nevertheless, engaging in sexual activity remains feasible, particularly with the use of sex hormone replacement therapy.

• Physical characteristics

Children diagnosed with Prader-Willi syndrome may exhibit distinct facial features, such as:

• • Ocular almond-shaped
  • Visual impairment
  • Narrow temporal forehead
  • A slender upper lip and a downward-bent stomach
  • Light hair, skin and eyes
  • Small hands and feet

• Cognitive impairment and developmental delay

The majority of individuals diagnosed with Prader-Willi syndrome have cognitive impairments and a below-average intelligence quotient (IQ). They will require an extended period to achieve significant developmental milestones. Children with this syndrome often sit at approximately 12 months and initiate walking at approximately 24 months. Many individuals experience speech difficulties and struggle with articulating certain phonetic sounds.

• Short-stature

Children diagnosed with Prader-Willi syndrome are typically shorter than children of the same age. This is typically present by the time the child reaches 2.

• Behavioral disorders, including compulsive behavior such as skin-picking and temper tantrums

Diagnosis

Prader-Willi syndrome is typically identifiable through genetic analysis. Genetic analysis may be recommended if a child has symptoms of Prader-Willi syndrome. Infants exhibiting significant physiological weakness upon delivery may also require genetic evaluation.

Management

Since Prader-Willi syndrome is incurable, current treatment focuses on managing the associated symptoms and complications. Beginning with the management of behavioral disorders and excessive appetite.

An essential aspect of providing care for individuals with Prader-Willi syndrome involves the maintenance of a healthy and typical body weight. Individuals afflicted with this condition should promptly embrace a nutritious and well-balanced diet, refraining from consuming sugary and calorie-dense food items or beverages. Individuals with Prader-Willi syndrome, if allowed unrestricted access to food, would rapidly develop obesity. Individuals afflicted with this illness can consume significantly larger quantities of food than others, yet they still experience hunger.

The dietary restriction will be extremely difficult. People with Prader-Willi syndrome may hide or steal food out of frustration and hunger.

Complications

Prader-Willi syndrome is not life-threatening. Nevertheless, excessive consumption of food and weight gain may lead to obesity-related diseases, including:

• Diabetes mellitus type 2
• Heart failure
• Dyspnea
• Increased food choking risk due to increased appetite

With proper dietary management and maintaining a healthy body weight, adults diagnosed with Prader-Willi syndrome can experience a high quality of life and achieve a life expectancy.

A lot of adults with Prader-Willi syndrome engage in activities such as volunteering or part-time employment; however, their prospects of achieving total independence are still considerably limited.

Prader-Willi syndrome is associated with developmental disorders affecting the sexual organs of both men and women. As a result, the onset of puberty will be impeded or insufficient, resulting in infertility.

Prevention

If you have a child diagnosed with Prader-Willi syndrome and plan to have more children, it is advisable to seek genetic counseling. A genetic counselor may evaluate and determine the risk of experiencing a similar disorder.

When to See a Doctor?

Regular newborn examinations can help detect initial indications of inadequate growth and development, which may indicate the presence of Prader-Willi syndrome or other related conditions.

If you have concerns regarding your infant's growth, development, and well-being, it is advisable to consult with a pediatrician.

Want to know more information about other diseases? Click here!