Low-Level Germline 48,XYY,+21 Mosaicism Associated with Transient Abnormal Myelopoiesis in a Phenotypically Normal Neonate.

Transient abnormal myelopoiesis (TAM) is a unique neonatal leukemoid reaction caused by a pathognomonic GATA1 mutation in conjunction with the gene dosage effect of trisomy 21, which is either of germline or somatic origin. We encountered a 48,XYY,+21 phenotypically normal neonate with Down syndrome who developed TAM due to cryptic germline mosaicism. Quantification of the mosaic ratio was complicated by an overestimation bias of hyperproliferating TAM within the germline component.

Neonatal subpial hemorrhage along the medial side of the temporal lobe: Two case reports.

Neonatal subpial hemorrhage has been underrecognized until recently and its pathophysiology remains unclear. Advances in magnetic resonance imaging have facilitated the identification of hemorrhage within the subpial space and cohort studies recently reported its imaging and clinical features. We encountered two cases of neonatal subpial hemorrhage along the medial side of the temporal lobe.

Sensitive detection of GATA1 mutations using complementary DNA-based analysis for transient abnormal myelopoiesis associated with the Down syndrome.

Introduction: GATA1 mutation plays an important role in initiating transient abnormal myelopoiesis (TAM) and in the clonal evolution towards acute megakaryoblastic leukaemia (AMKL) associated with Down syndrome (DS). This study aimed to develop and validate the clinical utility of a complementary DNA (cDNA) analysis in parallel with the conventional genomic DNA (gDNA) Sanger sequencing (Ss), as an initial screening test for GATA1 mutations.

Methods: GATA1 mutations were evaluated using both gDNA and cDNA in 14 DS patients using Ss and fragment analysis (FA), respectively.

Monocyte Chemoattractant Protein-1 (MCP-1) as a Potential Therapeutic Target and a Noninvasive Biomarker of Liver Fibrosis Associated With Transient Myeloproliferative Disorder in Down Syndrome.

Liver fibrosis is one of the common complications of transient myeloproliferative disorder (TMD) in Down syndrome (DS), but the exact molecular pathogenesis is largely unknown. We herein report a neonate of DS with liver fibrosis associated with TMD, in which we performed the serial profibrogenic cytokines analyses. We found the active monocyte chemoattractant protein-1 expression in the affected liver tissue and also found that both serum and urinary monocyte chemoattractant protein-1 concentrations are noninvasive biomarkers of liver fibrosis.

Two Japanese Patients With SMA Type 1 Suggest that Axonal-SMN May Not Modify the Disease Severity.

Background: Spinal muscular atrophy is caused by survival motor neuron gene SMN1 mutations. SMN1 produces a full-length SMN1 protein isoform encoded by exons 1-7, and an axonal-SMN protein isoform encoded by exons 1-3 and intron 3. The axonal-SMN protein is expressed only in the embryonic period and plays a significant role in axonal growth.

Intragenic mutations in SMN1 may contribute more significantly to clinical severity than SMN2 copy numbers in some spinal muscular atrophy (SMA) patients.

Background: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or intragenic mutation of SMN1. SMA is classified into several subtypes based on clinical severity. It has been reported that the copy number of SMN2, a highly homologous gene to SMN1, is associated with clinical severity among SMA patients with homozygous deletion of SMN1.

A case of Toriello-Carey syndrome with severe congenital tracheal stenosis.

Toriello-Carey syndrome is rare condition characterized by agenesis of the corpus callosum, the Pierre Robin sequence, and facial anomalies such as telecanthus, short palpebral fissures, and a small nose with anteverted nares [Toriello and Carey, 1988]. In addition, tracheal and laryngeal anomalies are common complications in patients with Toriello-Carey syndrome, and these anomalies can lead to death [Kataoka et al., 2003].

Epilepsy in children with trisomy 18.

Although the reported incidence of epilepsy associated with trisomy 18 is 25-50%, there have been no detailed descriptions of the characteristics of trisomy 18-related epilepsy. We investigated the characteristics of epilepsy in children with trisomy 18 who remained alive for over 1 year by sending questionnaires to pediatric neurologists belonging to the Kyoto Multi-institutional Study Group of Pediatric Neurology. Eleven patients with trisomy 18 were enrolled (age at the study, from 15 to 134 months; median, 43 months), of whom seven (64%) had epilepsy.