Genotype-phenotype correlation of rare 17q24.1-q24.3 microdeletion

Abstract

Although chromosome 17 shows high genetic instability, interstitial deletions within 17q24 region are very rare. The phenotype ofaff ected patients is heterogeneous but generally includes microcephaly, dysmorphic features, heart defects, intellectual disability,Andersen-Tawil syndrome and Carney complex. We present a 10-month-old proband with rare 5.4 Mb microdeletion of 17q24.1-q24.3 region. Her main clinical manifestations include microcephaly, distinctive dysmorphic features, and hypotrophy. Among 30deleted protein coding genes, we hypothesize that PRKCA, PSMD12, KPNA2, PRKAR1A, and KCNJ2 might be responsible for the proband’sphenotype. Changes in PRKCA gene have been described in patients with abnormal cognitive function and haploinsuffi -ciency of PSMD12 has been associated with neurodevelopmental disorders and dysmorphia. Deletions of KPNA2 gene, known to beinvolved in Nijmegen breakage syndrome, are characterized by microcephaly, short stature, and syndactyly. PRKAR1A gene is knownto be involved in Carney complex. Haploinsuffi ciency of KCNJ2 gene in this region causes episodes of muscle weakness and arrhythmia.So far, these symptoms have not been observed in the proband. Nevertheless, as these and additional comorbidities might developover time, continuous monitoring is required.Key words: 17q24.1-q24.3 microdeletion, CNV, PRKCA, PSMD12, KPNA2, PRKAR1A, KCNJ2, CMA