Phelan-McDermid syndrome presenting with developmental delays and facial dysmorphisms / 소아과

Phelan-McDermid syndrome is a rare genetic disorder caused by the terminal or interstitial deletion of the chromosome 22q13.3. Patients with this syndrome usually have global developmental delay, hypotonia, and speech delays. Several putative genes such as the SHANK3, RAB, RABL2B, and IB2 are responsible for the neurological features. This study describes the clinical features and outcomes of Korean patients with Phelan-McDermid syndrome. Two patients showing global developmental delay, hypotonia, and speech delay were diagnosed with Phelan-McDermid syndrome via chromosome analysis, fluorescent in situ hybridization, and multiplex ligation-dependent probe amplification analysis. Brain magnetic resonance imaging of Patients 1 and 2 showed delayed myelination and severe communicating hydrocephalus, respectively. Electroencephalography in patient 2 showed high amplitude spike discharges from the left frontotemporoparietal area, but neither patient developed seizures. Kidney ultrasonography of both the patients revealed multicystic kidney disease and pelviectasis, respectively. Patient 2 experienced recurrent respiratory infections, and chest computed tomography findings demonstrated laryngotracheomalacia and bronchial narrowing. He subsequently died because of heart failure after a ventriculoperitoneal shunt operation at 5 months of age. Patient 1, who is currently 20 months old, has been undergoing rehabilitation therapy. However, global developmental delay was noted, as determines using the Korean Infant and Child Development test, the Denver developmental test, and the Bayley developmental test. This report describes the clinical features, outcomes, and molecular genetic characteristics of two Korean patients with Phelan-McDermid syndrome.

Atypical teratoid rhabdoid brain tumor in an infant with ring chromosome 22 / 소아과

Reports of constitutional ring chromosome 22, r(22) are rare. Individuals with r(22) present similar features as those with the 22q13 deletion syndrome. The instability in the ring chromosome contributes to the development of variable phenotypes. Central nervous system (CNS) atypical teratoid rhabdoid tumors (ATRTs) are rare, highly malignant tumors, primarily occurring in young children below 3 years of age. The majority of ATRT cases display genetic alterations of SMARCB1 (INI1/hSNF5), a tumor suppressor gene located on 22q11.2. The coexistence of a CNS ATRT in a child with a r(22) is rare. We present a case of a 4-month-old boy with 46,XY,r(22)(p13q13.3), generalized hypotonia and delayed development. High-resolution microarray analysis revealed a 3.5-Mb deletion at 22q13.31q13.33. At 11 months, the patient had an ATRT (5.6 cmx5.0 cmx7.6 cm) in the cerebellar vermis, which was detected in the brain via magnetic resonance imaging.

Síndrome de Phelan McDermid: descripción de cinco pacientes e informe del primer caso descripto en gemelas siamesas / Phelan McDermid Syndrome: five patients description and report on the frst case described in conjoined twins

El síndrome de Phelan McDermid es producido por una pérdida de material genético, en un cromosoma del par 22, a nivel de la banda q13.3. Se describieron cinco pacientes con deleción 22q13.3 para correlacionar genotipo-fenotipo y comunicar el primer caso descripto en gemelas siamesas. Se registraron antecedentes perinatales, psicomotores, conducta, lenguaje y presencia de dismorfas. Se realizó cariotipo e hibridación in situ fuorescente (FISH) para región crítica 22q13.3. Presentaron hipotonía, dismorfas menores, retraso madurativo y retraso o ausencia del lenguaje. Se confrmó deleción 22q13.3 en los cinco pacientes, encontrándose una deleción en dos casos y un anillo del cromosoma 22 en tres, siendo uno con línea pura, y las siamesas, con mosaicismo, con una línea celular normal. En pacientes con clínica sugestiva y fenotipo evocador de síndrome velo-cardio-facial, se debe realizar cariotipo y FISH para región crítica 22q11.2 con sonda control 22q13.3, para detectar la deleción del Síndrome de Phelan McDermid.

Phelan McDermid Syndrome is caused by the loss of genetic material in a chromosome from pair 22, at the band q13.3. We describe fve patients with deletion 22q13.3 in order to establish a genotype-phenotype association, and report the frst case described in conjoined twins. We analyzed the perinatal history, psychomotor behavior, language, and the presence of minor dysmorphism. Karyotypes and in situ hibridization (FISH) for critical region 22q13.3 were performed to all patients. There were hypotonia, developmental delay, and delay or absence of language. A 22q13.3 deletion was detected in all patients described, two cases had a deletion and the other three had a ring of chromosome 22, one in a pure cell line, while the twins presented mosaicism. Karyotype and FISH for 22q11.2 critical region should be performed, with 22q13.3 control probe to detect the deletion of Phelan McDermid syndrome in all patients with clinical phenotype suggestive and evocative of velo-cardio-facial syndrome.