Fragile X Expert Interview with Dr. Rebecca Kronk

Each month, our Carrier Connections program features a different X-linked condition with the goal to increase awareness and education of X-linked conditions and how they impact females. This month, we are featuring Fragile X syndrome. Fragile X syndrome is a heritable X-linked disorder caused by an abnormality in the FMR1 gene. This gene makes the protein, FMRP, which plays a critical role in the development of nerve cells and the production of other cellular proteins. An issue in this FMR1 gene causes an absence or severe deficiency of the FMRP protein, resulting in a range of developmental problems and distinctive physical features. It typically results from a specific mutation, or alteration of DNA, that causes a CGG base repeat to occur over 200 times in the damaged FMR1 gene. Molecular genetic testing can be used to diagnose this condition by identifying the 200 CGG repeats in the FMR1 gene. Women with a fragile X premutation, or 55 to 200 repeats of the FMR1 gene, have an increased risk of having a child with fragile X syndrome.  Additionally, female fragile X premutation carriers may experience menstrual and menopausal abnormalities, infertility, diminished ovarian reserve, and chronic hypoestrogenism. Such chronic hypoestrogenism has been associated with impaired bone health and an increased risk of cardiovascular disease. Furthermore, female carriers of a fragile X premutation have been found to have neuropsychiatric issues including neuropathy, increased anxiety and depression, and tremor/ataxia syndrome. Some studies have also associated thyroid abnormalities and hypertension to fragile X syndrome in women.  Today, we are joined by Rebecca Kronk, PhD, MSN, CRNP, ANEF, FAAN, CNE. Dr. Rebecca Kronk joined Duquesne University School of Nursing as an Assistant Professor in August 2010, earned tenure in 2016 and was promoted to Full Professor in 2022. She is a board certified pediatric nurse practitioner. Dr. Kronk earned her MSN from the University of Pittsburgh School of Nursing and a PhD in Applied Development Psychology at the University of Pittsburgh, School of Education. Dr. Kronk was a fellow in the Maternal and Child Health Training program providing leadership and education in neurodevelopmental disabilities and autism (LEND) at the University of Pittsburgh. Dr. Kronk has been in the field of pediatric nursing for over 40 years and she is experienced in helping children and families with a range of developmental issues. She has enjoyed combining clinical work with teaching and research. The theoretical framework of her research has been based on the International Classification of Functioning, Disability, and Health published by the World Health Organization. Dr. Kronk has conducted several research studies on the sleep patterns of children with Fragile X syndrome and developmental functioning of children in the FXS gray zone alleles. Her ongoing research has focused on undergraduate educational interventions to promote learning in genetics and caring for people with disabilities. Carrier Connections is sponsored by Horizon Therapeutics, Sanofi, and Ultragenyx Pharmaceutical. For more information about our organization, check out rememberthegirls.org. National Fragile X Foundation Registry