ESPE Abstracts

Objective: This case report emphasizes the significance of early clinical examination in a pediatric endocrinology clinic for the diagnosis of Williams-Beuren Syndrome (WBS). WBS is a rare genetic disorder typically caused by a deletion in the chromosomal region 7q11.23. This deletion results in the loss of 25-27 genes, including the elastin gene. It is characterized by growth delay, mild intellectual disability, behavioral issues, cardiac diseases (mainly supravalvular aortic stenosis and peripheral pulmonary artery stenosis), connective tissue abnormalities, and endocrine disorders such as hypercalcemia, hypercalciuria, hypothyroidism, and early puberty. Distinct facial features include a depressed nasal bridge, hypertelorism, low-set ears, micrognathia, and a wide mouth with a prominent lower lip, giving an "elfin-like" appearance.

Method: The infant's history included being the second born of the mother's second pregnancy, delivery at 37+5 weeks via cesarean section due to preeclampsia, with birth weight 2470g, length 48cm, and head circumference 33cm. The infant had a brief NICU stay for transient tachypnea of the newborn, low birth weight, and jaundice, requiring phototherapy. At the age of 2 months, the infant was examined in the pediatric endocrinology practice for hypothyroidism and due to being small for gestational age (SGA). A pulmonic valve murmur (grade 3/6) was heard during the clinical exam. Additionally, the patient presented with hypertelorism, low-set ears, and a depressed nasal bridge. These findings raised the suspicion of a genetic disorder. Pediatric cardiology evaluation revealed right ventricular hypertrophy, moderate peripheral pulmonary stenosis with a possible supravalvular membrane, and mild aortic stenosis. Thyroid function tests indicated hypothyroidism, which led to thyroxine treatment. Given the suspicion of a genetic syndrome, both standard karyotyping and molecular karyotyping (array-comparative genomic hybridization) were performed, revealing a 1.4 Mb deletion in the 7q11.23 region, confirming WBS.

Results: The most recent follow-up, at six months post-diagnosis, showed normal thyroid hormone levels, and the infant continued on thyroxine treatment. However, the infant remained below the 3rd percentile for height and weight, necessitating monthly monitoring. A follow-up cardiology evaluation was recommended in three months.

Conclusion: Clinical examination was pivotal for diagnosing WBS at an early age. Observing the systolic murmur at the pulmonary valve raised the suspicion of a genetic disorder, leading to a definitive diagnosis. The notably early diagnosis of WBS in this case, much earlier than the average age of 4-5 years, underscores the potential for significantly improved outcomes through clinical assessment, ultimately benefiting our patients and their families.