Transient Hemi-Lower Limb Ischemia in the Newborn: Arterial Thrombosis or Persistent Sciatic Artery?

Neonatal thromboembolism occurs with various predispositions and triggers. Early diagnosis of the thrombosis is challenging and essential for the therapeutic interventions. We herein report two newborns who presented with transient hemi-lower limb ischemia due to (1) arterial thrombosis or (2) a persistent sciatic artery (PSA). The patient with arterial thrombosis showed elevations of fibrin degradation product and D-dimer and received antithrombin and heparin intravenously. The patient with PSA was immediately assessed by a contrast-enhanced computed tomography because of a transient ischemic episode with no evidence of hypercoagulability. Newborns suspected of having arterial thrombosis may need urgent surgical intervention along with thrombolytic and anticoagulant therapy to prevent organ ischemia and amputation of extremities. Conversely, some PSA cases have reportedly been treated conservatively. This vascular anomaly was previously reported as a cause of lower limb ischemia only in a newborn. PSA is a critical differential diagnosis of neonatal arterial thrombosis that needs urgent therapeutic intervention.

Wiskott-Aldrich syndrome in a girl caused by heterozygous WASP mutation and extremely skewed X-chromosome inactivation: a novel association with maternal uniparental isodisomy 6.

Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by microthrombocytopenia, eczema and immune deficiency, caused primarily by mutations in the WASP (Wiskott-Aldrich syndrome protein) gene. Female carriers are usually asymptomatic because of the preferential activation of the normal, nonmutated X-chromosome in their hematopoietic cells. We report our observations of a female child with WAS, who displayed symptoms of congenital thrombocytopenia. DNA sequencing analysis of the WASP gene revealed a heterozygous nonsense mutation in exon 10. The expressions of WASP and normal WASP mRNA were defective. We found preferential inactivation of the X-chromosome on which wild-type WASP was located. Single-nucleotide polymorphism microarray testing and the analysis of the polymorphic variable number of tandem repeat regions revealed maternal uniparental isodisomy of chromosome 6 (UPD6). Our results underscore the importance of WASP evaluation in females with congenital thrombocytopenia and suggest that UPD6 might be related to the pathophysiology of nonrandom X-chromosome inactivation.

A case of pontine tegmental cap dysplasia with comorbidity of oculoauriculovertebral spectrum.

Pontine tegmental cap dysplasia (PTCD) is a newly described brainstem malformation with distinct neuroimaging findings, characterized by a flattened ventral pons, cerebellar vermal hypoplasia and vaulted pontine tegmentum that forms a "caplike" or "beaklike" bulge projecting into the fourth ventricle. We describe a 3-month-old infant male who presented with typical neuroradiological findings as well as clinical features of PTCD. Notably, he manifested multiple anomalies with left ocular and facial hypoplasia, bilateral sensorineural hearing loss and rib and vertebral anomalies. Oculoauriculovertebral spectrum (OAVS) was thus considered to be an accompanying phenotype of this patient. The unique comorbidity seen in this patient suggests that PTCD and OAVS may partly share a common mechanism in their pathogenesis.