De Novo Mosaic 6p23-p25.3 Tetrasomy Caused by a Small Supernumerary Marker Chromosome Presenting Trisomy Distal 6p Phenotype: A Case Report and Literature Review.

Small supernumerary marker chromosomes (sSMCs) derived from the chromosome 6 short arm are rare and their clinical significance remains unknown. No case with sSMC(6) without centromeric DNA has been reported. Partial trisomy and tetrasomy of distal 6p is a rare but clinically distinct syndrome. We report on a de novo mosaic sSMC causing partial tetrasomy for 6p23-p25.3 in a male infant with symptoms of being small for gestational age, microcephaly, facial dysmorphism, congenital eye defects, and multi-system malformation. Conventional cytogenetic analysis revealed a karyotype of 47,XY,+mar [25]/46,XY [22]. Array comparative genomic hybridization (aCGH) revealed mosaic tetrasomy of distal 6p. This is the first case of mosaic tetrasomy 6p23-p25.3 caused by an inverted duplicated neocentric sSMC with characteristic features of trisomy distal 6p. Comparison of phenotypes in cases with trisomy and tetrasomy of 6p23-p25.3 could facilitate a genotype-phenotype correlation and identification of candidate genes contributing to their presentation. The presentation of anterior segment dysgenesis and anomaly of the renal system suggest triplosensitivity of the FOXC1 gene. In patients with microcephaly growth retardation, and malformation of the cardiac and renal systems, presentation of anterior segment dysgenesis might be indicative of chromosome 6p duplication, and aCGH evaluation should be performed for associated syndromic disease.

Coronary Diameters in Taiwanese Children Younger than 6 Years Old: Z-Score Regression Equations Derived from Body Surface Area.

BACKGROUND: The measurements of coronary diameters, usually obtained by 2-dimentsional echocardiography, play important roles oin the management and follow-up of Kawasaki disease (KD). However, in Taiwan, domestic normgrams and a Z-score calculator for coronary artery diameters are still not available. METHODS: Echocardiography was performed on 412 healthy children younger than 6 years of age. The appropriate exponential regression model was fitted to correspond with body surface area (BSA). The computed Z-scores of all subjects were also tested for normal distribution. RESULTS: Using the model ln (measurement) = ß1 + ß2 × ln (BSA), the adjusted R(2) values were 0.611 and 0.484 for the models of the left main coronary artery (LMCA) and the right (RCA), respectively. Analysis of computed Z-score distribution showed acceptable goodness of fit for a normal distribution [p = 0.90 (LMCA); p = 0.17 (RCA)]. CONCLUSIONS: We have established reference ranges for the coronary artery diameters in Taiwanese children younger than 6 years of age. The regression equations and Z-score calculators for the LMCA and RCA provide an objective determination of coronary dilatation in a large population, which is important for the care and medical management of KD patients in Taiwan. KEY WORDS: Coronary diameter; Kawasaki disease; Taiwan; Z-score.

Severe esophageal burn following chloral hydrate overdose in an infant.

Chloral hydrate is generally considered to be a safe hypnotic drug, and is commonly used for short-term sedation before diagnostic procedures. Its irritant actions to the mucous membranes are usually limited. We report a rare complication of chloral hydrate overdose in an infant. An 8-month-old male infant became unconscious and required ventilation support after an overdose of chloral hydrate was administered to provide sedation for an ophthalmologic examination. White plaques and sloughing of the oropharyngeal mucosa were observed on the next day. Esophagogastroscopy revealed severe corrosive lesions on the whole esophagus. The child recovered after supportive treatment and his oral intake remained well without dysphagia after 1 year. This report illustrates the potential corrosive effect of chloral hydrate. Strict attention should be paid to the dosing and administration protocol of chloral hydrate in infants. The condition of the oropharyngeal mucosa should be carefully monitored after chloral hydrate administration.

Hybrid angioplasty for left pulmonary artery stenosis after total correction of tetralogy of Fallot: report of one case.

Pulmonary artery stenosis is common in tetralogy of Fallot. Surgical correction usually achieves good results. For those patients undergoing total correction with residual pulmonary artery stenosis, percutaneous transluminal angioplasty (PTA) plays an important role. However, this might not be possible for complex anatomies. We report a 19-month-old boy who underwent total correction of tetralogy of Fallot at 1 year of age. He developed main pulmonary artery (MPA) aneurysm and left pulmonary artery (LPA) stenosis 4 months after the operation. PTA was attempted, but the guidewire failed to thread into the LPA due to the dilated MPA and tiny LPA ostium. A hybrid approach consisting of left anterior small thoracotomy and balloon angioplasty via the introducer sheath in the MPA was proposed. Rapid access to the LPA and successful balloon angioplasty followed by stenting concluded the hybrid intervention. Such intervention is a good alternative to treat this complex anatomy.

Intra-retroperitoneal duplication cyst.

Duplication cyst occupying the retro- and intra-peritoneal space is a rare condition. We describe a case of duplication cyst in a 13-year-old girl who presented with abdominal pain, vomiting, and a lower abdominal mass. Plain abdominal X-ray films revealed local ileus over the lower abdomen. Ultrasonography revealed 2 double-layered cystic masses over the lower abdomen with a suspicious communicating tract. Mild hydropelvis of the right kidney was also noted. Abdominal computed tomography revealed 2 cystic lesions. One was located at the pelvic cavity just above the urinary bladder and the other was in the left retroperitoneal space. Laparotomy revealed a dumbbell-shaped intra-retroperitoneal duplication cyst with a small communicating tract. The cyst was excised without disturbing bowel continuity and the vascular supply. The patient was doing well at 1-year follow-up.

Use of extracorporeal membrane oxygenation to rescue a newborn with early-onset group B streptococcal sepsis and cardiopulmonary failure.

Group B streptococcal (GBS) infection is an important cause of perinatal morbidity and mortality. We report the use of extracorporeal membrane oxygenation (ECMO) to rescue a newborn with refractory GBS sepsis and meningitis who developed cardiopulmonary failure. This 2-day-old infant weighed 2640 g and was born to a healthy mother at full term. Respiratory distress, hypotension, and persistent pulmonary hypertension developed on the second day of life. The clinical condition deteriorated rapidly despite conventional treatment, and venoarterial ECMO was established to rescue this moribund newborn. During ECMO, the patient regained stable hemodynamics and good oxygenation, and infection was controlled. ECMO was used for 90 hours and the baby was weaned smoothly. Neurologic assessment after ECMO revealed hydrocephalus, abnormal electroencephalogram, and increased brain auditory evoked potential threshold. This report emphasizes that ECMO may be considered to rescue neonatal patients with cardiopulmonary failure due to GBS sepsis. Possible neurologic complications after ECMO should be carefully monitored.