[P3-154] Pallister-Killian Syndrome: Clinical Characteristics and Genetic Diagnosis
[Introduction] Pallister-Killian syndrome (PKS) is a rare, multisystemic disorder caused by isochromosome 12p or tetrasomy 12p with highly variable tissue-limited mosaic pattern. In this study, we described the clinical characteristics and the genetic diagnosis of PKS.
[Methodology] The five patients diagnosed with PKS through the identification of additional copies of chromosome 12p were included in this study. The medical records of the patients were reviewed retrospectively.
[Results] They had characteristic craniofacial features in common such as frontal bossing, frontotemporal sparseness of hair, midline facial hypoplasia, low-set ears, and hypertelorism. Several abnormal findings of antenatal ultrasound were reported in three patients: one polyhydramnios, one placenta previa, and one congenital heart disease. Delayed development and axial hypotonia were observed in all patients. Only one patient had seizures due to multifocal cerebral infarction, while other three patients showed structural abnormalities on brain imaging including periventricular leukomalacia and polymicrogyria. In addition, multi-systemic medical problems were observed including cardiac anomalies (n = 3), hearing impairments (n = 4), visual problems (n = 3), skeletal defects (n = 3), and intestinal structural anomalies (n = 2). We confirmed the diagnosis for two by using array-based comparative genomic hybridization and the remaining patients by fluorescence in situ hybridization analysis of peripheral blood cell or buccal smear.
[Conclusion] PKS is characterized by distinctive facial dysmorphism, multiple congenital anomalies, profound intellectual disability, and seizures. Clinical suspicion is imperative for the recognition of PKS, because proper cytogenetic tests are needed to confirm the diagnosis and provide genetic counseling.
[Methodology] The five patients diagnosed with PKS through the identification of additional copies of chromosome 12p were included in this study. The medical records of the patients were reviewed retrospectively.
[Results] They had characteristic craniofacial features in common such as frontal bossing, frontotemporal sparseness of hair, midline facial hypoplasia, low-set ears, and hypertelorism. Several abnormal findings of antenatal ultrasound were reported in three patients: one polyhydramnios, one placenta previa, and one congenital heart disease. Delayed development and axial hypotonia were observed in all patients. Only one patient had seizures due to multifocal cerebral infarction, while other three patients showed structural abnormalities on brain imaging including periventricular leukomalacia and polymicrogyria. In addition, multi-systemic medical problems were observed including cardiac anomalies (n = 3), hearing impairments (n = 4), visual problems (n = 3), skeletal defects (n = 3), and intestinal structural anomalies (n = 2). We confirmed the diagnosis for two by using array-based comparative genomic hybridization and the remaining patients by fluorescence in situ hybridization analysis of peripheral blood cell or buccal smear.
[Conclusion] PKS is characterized by distinctive facial dysmorphism, multiple congenital anomalies, profound intellectual disability, and seizures. Clinical suspicion is imperative for the recognition of PKS, because proper cytogenetic tests are needed to confirm the diagnosis and provide genetic counseling.