Handbook of Genetic Counseling/XXX Syndrome

XXX Syndrome

Introduction

• Greet family and acknowledge prior contact.

Contracting

• Discuss the reason for referral - amniocentesis results.
• Express empathy over what a surprise the diagnosis was for the family.
• Assess their main questions and concerns and find out what they hope to gain from the session.
• Find out how much reading/research they have done on XXX Syndrome and assess the degree of their knowledge about heredity and genetics.
• Explain our intent to address their concerns and questions about Triple X. Explain that we will share information about the syndrome, discuss the test results, how the syndrome is caused, recurrence risks, problems associated with Triple X, and medical management.

Elicit Medical History

• Maternal and paternal age
• Ethnicity
• Consanguinity
• Chronic illnesses

Elicit Family History

• Construct pedigree
• Identify possible risks

Pregnancy History

• Review information from intake.
• G (# of pregnancies), P (# of live births), SAb, EAb
• Exposures/medical complications (infection, fever, rash, medication, smoking, alcohol, recreational drugs, x-rays, bleeding)

Genetics of XXX Syndrome

• 47, XXX karyotype
• Inheritance pattern: chromosomal abnormality caused by non-disjunction (possible correlation to advanced maternal age)
• Prevalence: 1 in 1,000 females
• Recurrence risk: less than 1%

Natural History and Clinical Features of XXX Syndrome

• At birth, girls with Triple X show no physical stigmata and are normally developed. The infants may have a lower than normal birth weight.
• These girls are described as being quiet and passive babies with a lower assertive age during childhood.
• They are usually delayed in motor, speech, and psychosocial development with delayed emotional maturation.
• Tall stature (at the 80th percentile by adolescence, with an average adult height of 172 cm).
• Comparatively low weight in comparison to height.
• Lower head circumference (25th - 35th percentile)
• Back problems may develop due to weak musculature.
• Lower IQ (average is approximately 90) - however, mental retardation is very rare. May have learning difficulties in school that require outside help.
• Normal puberty and average onset of menstruation.
• Fertile, with the possibility of early menopause.
• No increased risk of disease or mental illness.

Diagnosis and Testing of XXX Syndrome

• Diagnosis by amniocentesis, CVS, or chromosome testing.
• Recurrence risk of less than 1%.
• There is a theoretical increased risk of X aneuploidy for the children of women with Triple X, however, this has not been shown in practice. A less than 1% risk figure is quoted, but genetic counseling is suggested to explain the possibility of prenatal diagnosis if desired.

Management

• Early intervention programs with mental, social, and motor stimulation are suggested to help prevent possible developmental delay.
• Speech therapy is recommended to counteract speech delays.
• Participation in team sports and group activities is suggested to improve motor skills and psychosocial adaptation.
• Schools should provide special education or resource help for learning difficulties.

Psychosocial Issues

• Self-fulfilling prophecy leading to a behavior problem
• Should they tell their pediatrician?
• Should they tell their daughter's teachers?
• Should they tell their daughter?

Resources

• The Turner Center

Psychiatric Hospital Aarhus

Skovagervej 2 DK-8240

Risskov Denmark

www.aaa.dk/turner/engelsk

• Klinefelter Syndrome and Associates

PO Box 119

Roseville, CA 95678-0119

(916) 773-2999

www.genetic.org

• Website on Triple X Syndrome

www.triplo-x.org

• Website with family stories

www.voicenet.com/~markr/triple.html

Notes

The information in this outline was last updated in 2002.