Aarskog Syndrome

What is Aarskog Syndrome?

Aarskog Syndrome is a rare genetic disorder that affects many body parts and is characterized by stunted growth. The disorder does not manifest until the child reaches about 3 years of age and usually affects:

• Facial features (nose, mouth, ears, forehead etc)
• General stature (height)
• Muscles
• Bones (spine, hands, fingers, toes)
• Genitalia (testis, scrotum)

Other Names

The disorder is identified with many names which are:

• Aarskog-Scott syndrome
• AAS
• Aarskog disease
• Scott Aarskog syndrome
• Facio-digito-genital syndrome or facial digital genital syndrome
• Facio-genital dysplasia or facial genital dysplasia

Causes

For AAS, there are many causes some of which are unknown. The most common cause is mutation that occurs in the facio-genital dysplasia genes (FDGI). Cdc42 that is usually activated by this gene in turn relays vital signals for embryonic development.

Risk factors include gender and genetic makeup. Males are at a higher risk of getting the disorder as compared to females.

Who is Affected ²

The inheritance pattern of this disorder is the X-linked recessive pattern where the gene causing it is found on the X chromosome. Males have the XY chromosomes and one copy of the mutated gene is enough to cause Facio-genital dysplasia while for females it requires a copy on both chromosomes to cause it.

The chances of double copy of mutated FDG1 on female chromosomes are quite rare thus the disorder is commonly found in males.

Females with a single copy of the FDG1 gene show mild signs such as:

• Short physique
• Hypertelorism
• Widow’s peak hairline

Prevalence of the Disorder²

For Scott Aarskog syndrome, the frequency of how it occurs is quite unknown owing to the fact that most people are not informed of the disorder since it does not have high recognition. On the other hand, those who are mildly affected are not included to the list due to lack of diagnosis.

Signs and Symptoms

Aarskog-Scott syndrome’s signs and symptoms occur based on the affected body part. This is evidenced through:

Facial features

• Rounded face
• Broad forehead
• Poorly developed mid-section of the face
• Widely spaced eyes (ocular hypertelorism)
• Widow’s peak hairline
• Slanted eyes
• Crossed eyes
• Farsightedness
• Sagging/drooping eyelids (ptosis)
• Indentation on the upper lip
• Folding on the top part of the ears
• Fleshy earlobe
• Teeth growth takes long
• Extensive furrow on the upper lip (philtrum)
• Underdeveloped enamel (enamel hypoplasia)
• Cleft palate
• Small nose with forward slanting nostrils
• Wide nasal bridge

Brain development

Children who are born with the disorder may show slow brain development but have good social skills. The disorder also shows other symptoms such as:

• Slow cognitive performance
• Cognitive development is delayed
• Attention Deficit Hyperactivity Disorder (ADHD)

Bone structure and muscle

• Short stature
• Short stubby fingers and toes
• Single crease on the palms
• Curled little finger (pinky)
• Fingers and toes are webbed
• Finger joints may be abnormally extendible
• Flat and wide feet that have bulbous toes
• Indentation on the chestor sunken (pectus excavatum)
• Spina bifidaocculta (closure of the spinal column bones)
• Fusion of some bones (such as that of the hands)
• Protruding navel (belly button)

Genital complications

• Hernia in the scrotum (lump in the groin)
• Testicles (one or both) have not descended into the scrotum
• Shawl scrotum (extended skin fold around the penis)
• In some cases the urinary opening may be located under the penis
• Clefted scrotum
• Sexual maturity is delayed

Disorders Related to AAS ¹

The Facio-digito-genital syndrome is the only dosorder showing these many signs and symptoms. Other related disorders include:

• Noonan syndrome which is diagnosed at birth
• Robinow syndrome. Similar to Aarskog-Scott Syndrome, it is characterized by short stature owing to stunted/delayed growth.

Diagnosis

AAS can be diagnosed when the child reaches 3 years of age. Diagnosis entails:

• Clinical examination of the facial features
• Extensive evaluation of the patient’s history to build on the findings
• Full physical examination
• X-rays for bone structure evaluation in order to rule out other similar disorders
• Genetic testing confirmation.

^Treatment

Aarskog syndrome is a life long disorder with no cure but that does not mean there is nothing doctors can do. Where medics play a part is in treating the symptoms manifested by this condition meaning thatthe treatment is symptom specific.

Coordinated treatment by specialists from various fields such as cardiologists, pediatricians, speech pathologists, dental specialists, audiologists, opthamologists, surgeons and any other practitioner that may be required.What can be done:

• Surgery may be required in case of congenital as well as structural malformations
• Orthodontic and dental surgery for restructuring teeth, cleft palates and other oral complications.
• Hernia repair surgery
• Testicular surgery to enable testicles to descend into the scrotum
• Genetic counseling

For Attention Deficit Hyperactivity Disorder:

• Specialist assistance for delays in the cognitive development
• Psychiatrist assistance
• Behavioral specialist counseling for parents

Prevention

There is no prevention for AAS. Parents can undergo genetic testing beforehand and get to know if they are carriers of the mutated gene and decide on whether to have children or not.

Support Groups 

Since aarskog syndrome is a lifelong disorder, parents of a child having the disorder need support from relatives, the community as well as specialists to guide them in raising him or her.

In doing so, some parents with children with the disorder come together to share their experience and challenges they face while taking care of these special children. For this reason support groups come into play.

Support groups are beneficial in different ways some include:

• Parents gain from the educational materials such as brochures, pamphlets
• AAS experts may intervene in training parents on how best to care for the special kids
• Support groups may attract donors making it easy for parents to meet the expensive medical bills arising from the various X-rays needed, gene testing, and surgical procedures that may be required.
• Joining a support group keeps you informed which will translate in how to look after your child.

When to See a Doctor

Immediately you notice any of the signs and symptoms on your child, see a doctor for further investigation and advice.

Reference List

1. Aarskog syndrome. Retrieved from https://rarediseases.org/rare-diseases/aarskog-syndrome/
2. Aarskog-Scott syndrome. Retrieved from https://ghr.nlm.nih.gov/condition/aarskog-scott-syndrome#resources
3. Aarskog Syndrome: Causes, Risk Factors and Diagnosis. Retrieved from http://www.healthline.com/health/aarskog-syndrome#overview1
4. Aarskog – Scott Syndrome. Retrieved from http://www.medindia.net/patients/patientinfo/aarskog-scott-syndrome.htm
5. Aarskog- Scott Syndrome. Retrieved from https://ghr.nlm.nih.gov/condition/aarskog-scott-syndrome