Medical Providers/ Pediatricians
Meet our friendly, experienced pediatricians and staff at A to Z! Our entire team is dedicated to helping you and your child feel at home from the moment your walk through the door. We're proud to be members of the Addison and Brookfield communities and serve the needs of their children.
We pride ourselves in being an exceptional clinic where children come first. Our child-focused practice works hard to meet the needs of children from infancy through adolescence. Compassionate, knowledgeable and supportive staff is the cornerstone of A to Z Pediatric and Youth's quality care. All of our pediatricians and medical staff are highly trained professionals, and maintain the highest level of accreditation in pediatrics to address the special needs of infants, children, and teens.
We strive to treat each and every patient as we would want our own children to be treated. Our doctors and staff look forward to building a relationship with you and your family.
W Daniel Perez, MD, FAAP 
Dr Perez founded A to Z Pediatric and Youth Healthcare in 2010 with the strong motivation to provide optimal pediatric healthcare to the children of the West and near West Suburbs. His vision encompasses providing a memorable positive experience in pediatric primary care using a model of excellence in pediatrics as well as meeting the challenging needs of children in areas of behavior and mental health and nutrition. Dr Perez has more than 20 years experience in the field of pediatrics and has a special interest in the mental health problems, behavior and development and nutritional problems of children and adolescents
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Gloria Valiente, MD, FAAP
Dr Valiente is an enthusiastic, experienced, and Board certified pediatrician confident in caring for patients from infancy through adolescence. She offers comprehensive healthcare with an individualized approach. She has over 18 years of outpatient experience in both city and suburban pediatric practices. Some of her clinical interests are skilled health supervision and early detection of developmental concerns and delays. She offers optimal care of asthma and allergic related conditions, as well as the prevention and management of obesity and related morbiditiesDr. Valiente is an enthusiastic and experienced Board Certified pediatrician joining A to Z Pediatric and Youth Health care in January 2016. She strives to confidently provide high quality and comprehensive pediatric health care using a culturally sensitive and individualized approach. She graduated medicine in Illinois and has practiced in urban, as well as, suburban locations in private practice and community based medicine. She has practiced pediatrics in both California and Illinois. She has years of experience in pediatric health maintenance and supervision and the care of chronic conditions.
Jill Whelan, MSN, APN, CPNP
For the first six years of her career she worked as a registered nurse in the areas of NICU, and Labor and Delivery. Later, she earned herMasters Degree in Nursing and became licensed to practice as a Pediatric Nurse Practitioner (PNP)
Jill has been working as a PNP, providing both well and sick care to infants through adolescents, since 2004. One of the areas that specializes working with both children and their families, is on weight concerns. She has a personal interest in promoting healthy lifestyles as well as providing education in the areas of eating right, and exercise in order for families to life happy, productive lives. What she enjoys most are the opportunities to educate parents on age-related developmental and behavioral issues.
It is a privilege to be entrusted with the health care of children. Jill believes that quality care is based on the individual needs of the family and the child. She does her best to treat children in a kind manner based on their developmental level as well as their age.
She is certified by the National Association of Nurse Practitioners. Jill's free time is spent with her husband, two young babies and three dogs.