Pituitary Dwarfism

Overview of Causes of Dwarfism

Dwarfism as an entity can be caused by many problems, and most are genetic mutations or less commonly another medical condition. Technically, the definition of dwarfism is based on height, that being less than 4 foot 10 inches tall. Cases of disproportionate dwarfism are characterized as having short stature, but the limbs are shorter than normal, and head appears large- some signs are evident at birth allowing for early diagnosis. Proportional dwarfism, in addition to having short stature, is typically due to delayed or slow growth and produces appropriate body proportions since the growth of bones as well as other body structures are delayed as well. For this reason, this form of dwarfism is usually diagnosed when the growth rate drops off.

All of the causes of dwarfism are clearly discovered due to a levelling off of a child’s growth over time, when compared to normal children’s growth rate over the same period. This is a condition that makes tracking a child’s growth on a standardized growth chart critical. When recognized appropriately, pituitary derived dwarfism can be treated, and normal growth can be achieved with appropriate medication.

What is the Pituitary and what does it do?

This is a critical gland in the human body. It sits behind the nasal bridge, between and behind the eyes. The pituitary gland secretes hormones that are essential to normal bodily function. The anterior (front) side of the pituitary makes six hormones: growth hormone, adrenocorticotropic hormone, thyroid stimulating hormone, prolactin, follicle stimulating hormone, and luteinizing hormone. The posterior (back) of the gland produces antidiuretic hormone and oxytocin.

Picture showing the pituitary gland and hypothalamus

In the case of Pituitary Dwarfism, there is a decrease or absence of Growth Hormone (GH) from the pituitary. Some of these cases can occur due to mutation, but most cases have no known cause. However, the condition can be a part of Panhypopituitarism- where all hormones are low(and is beyond the scope of this discussion), or only hypopituitarism that can occur at birth or be acquired by trauma, or postoperatively. In either case, given the inadequate supply of GH, a few flags are raised on physical exam:

• Height is below the 3% mark on standardized growth charts
• The growth rate is slower than is expected by depicted on age appropriate growth charts
• Delayed sexual development is evident when the child is a teenager
• Poor growth of internal organs can cause a myriad of issues

Determining there is a Dwarf-related Growth Disorder

Picture of Pituitary dwarfism – Diagram showing the tumor causing hypopituitarism (decreased hormonal output)

• Regular well-child visits must be kept, and the child’s weight, height and head circumference should be noted regularly and plotted on standardized growth charts.
• Proper physical exam needs to be done and may recognize abnormal features in the head or axial skeletal growth delays.
• X-rays are usually required to determine the child’s bone age. The child may have limbs that are short compared to same age normals, and a “bone-age” can be ascertained. In dwarfism cases, the child’s bone age is typically at least two years younger than his chronological age.
• If Pituitary dwarfism is of concern, an MRI of the brain can show abnormalities in this area.
• There is genetic testing available for dwarf related concerns, however they are not required for diagnosis, excepting to diagnose Turner’s syndrome.
• An accurate family history needs to be taken to rule out certain genetic risks
• Finally, lab work is indicated to assess growth hormone levels, among others

What are the Treatments for Pituitary Dwarfism?

Pituitary dwarfism Characteristics – Large head with prominent forehead and Normal-sized torso with short arms and legs

Surgical

Patients with disproportionate dwarfism may require corrective surgeries to repair limb problems, spinal compression, lengthening of the limbs, and placement of a shunt to drain excessive spinal fluid in the brain. These surgeries are not indicated for growth hormone deficient dwarfs.

Hormone Therapy

Growth Hormone Deficiency/Pituitary Dwarfism – Children found to have a growth hormone deficiency need to be diagnosed as early as possible so that they may initiate growth hormone injection therapy. With these injections, a child can mount a full growth spurt and reach a normal adult height. Typically, this requires daily injection therapy for many years. Therapy may be required for years of adulthood, or even lifelong. Other hormones from the anterior pituitary may also be deficient

Achondroplasia

This is the most common cause of inborn genetic abnormality resulting in disproportionate dwarfism. Hormonal treatment for achondroplasia does not affect growth at all.

Turner’s Syndrome

Women with Turner’s have the genetic Chromosomes XO, and the absent chromosome creates the problems that occur. Turner’s patients have normal mental development, but have ovarian streaks, or absence, and therefore require estrogen replacement and often other hormone replacement. They will require hormones throughout their life until a menopausal age.

Lifelong Considerations

Medical care – People with dwarfism need to have regular visits, for preventive medical care. In the case of Achondroplasia, more frequent visits are indicated as bones may grow irregularly, into inappropriate positions, and cause problems in the spine.

Emotional and Spiritual Care (specific to Pituitary Dwarfism)

• Engage your child in as many activities as they wish to participate. Social and self- esteem issues are greatly accentuated in structured group activity. In addition, aerobic exercise will increase endorphins, improve mood, and physical health.
• Nonprofit groups are a viable source for help, advice, and general social support. In addition to providing disease related information, connecting similar patients with each other for self-advocacy, and the sharing of resources. Such an organization is the Little People of America.
• Safety Issues are important in the living environment of a little person. The door frames need to be accommodating, the handles for the doors, peepholes, toilet height, lower stair rails, smaller steps, lowering light switches, etc.
• Referral to an Occupational therapist will enable the recommendation of adaptive gear for ease of use to go about the day’s activities without hindrances.
• Seek out counseling services, as any little person at a young age will need support and coping skills to avoid negative reactions to the insensitivity of other children.
• Connect the child to school guidance services so that school related problems can be addressed quickly and consistently.
• Connect to school personnel, request an Individual Education Plan (IEP) under due process so that any supportive or educational services may be offered and monitored.