About the Klinefelter Program
Who we treat
The Klinefelter Program at Children’s Hospital of Philadelphia treats children and adolescents who have been diagnosed with Klinefelter syndrome (also known as 47,XXY), a genetic condition in which a boy is born with an extra X chromosome. We also treat children with other X and Y chromosome variations, such as 48,XXXY or 47,XXX. We work with patients and families from infancy through early adulthood, providing multidisciplinary assessment, treatment and care planning — all during a single clinic appointment.
The Klinefelter Program is part of CHOP’s Adrenal and Puberty Center, which has expertise in treating children with an array of conditions that may affect puberty and gonadal function. The Adrenal and Puberty Center is under the Division of Endocrinology and Diabetes.
What we do
Our program follows children with Klinefelter syndrome and other X and Y variations from birth into young adulthood. During the initial visit, clinicians from Endocrinology, Clinical Genetics and Psychology collaborate as a multidisciplinary team to provide assessment, treatment and guidance. After the initial consultation, children are followed with regular appointments by our endocrine team.
To address all the psychosocial needs of patients and families, we offer ongoing support with a dedicated psychologist and social worker. The psychology and social work follow-ups are coordinated to occur at the same time as the endocrine visit. Psychology visits are also available by telehealth.
Your child will receive a comprehensive evaluation, and you will be provided with an ongoing care plan, which includes referrals for additional treatment and therapy as needed. Children will have access to hormone therapy treatment if it is part of their treatment plan.
Assessments and treatments
Assessments and treatments offered through the Klinefelter Program include:
- Consultation for families with a newborn with Klinefelter or other X and Y chromosome variations
- Puberty monitoring and testosterone replacement therapy according to your child’s needs
- Comprehensive assessment of all your child’s needs and appropriate referrals to various specialties, such as reproductive urology for fertility counseling
- Monitoring of complications associated with Klinefelter, such as screening for high cholesterol levels, diabetes or osteoporosis
- Developmental, neurocognitive and ADHD screenings
- Patient and family support to cope with the medical condition and to understand and adhere to medical treatments
- Family support in issues related to school (such as early intervention, an Individualized Education Plan or 504 plan) and vocational planning
Additional support
The clinicians involved with the Klinefelter Program host patient/family conferences and participate in Klinefelter syndrome research. Many patients and families appreciate the opportunity to learn about the latest research and treatment options at these conferences and to connect with others who are also affected by the condition.
Our program works closely with support groups, such “Living with XXX” and the Association for X and Y Variations (AXYS), an advocacy, education and support organization for individuals with X and Y chromosome variations and their families. We are part of AXYS clinical and research network.
Our patients also may be eligible for participating in national research studies or studies developed by one of our research collaborators.