Congenital central hypoventilation syndrome is a rare genetic disorder that affects control of breathing caused by variants in the paired-like homeobox 2B (PHOX2B) gene. During pregnancy, women with congenital central hypoventilation syndrome are at risk for hypoventilation and require frequent assessments of oxygenation and ventilation during wakefulness and sleep on their ventilator. This could potentially lead to adjustments in the ventilator settings or a change in the assisted ventilation modality. We report the case of a 31-year-old pregnant woman with congenital central hypoventilation syndrome and an implanted cardiac pacemaker who underwent prenatal genetic testing for congenital central hypoventilation syndrome and who delivered a healthy newborn by cesarean delivery. She received collaborative multidisciplinary care from a team that included specialists in obstetrics, maternal and fetal medicine, medical genetics, sleep and pulmonary medicine, cardiology, and anesthesiology. She used bilevel positive airway pressure therapy throughout pregnancy and after cesarean delivery without requiring adjustments in the bilevel positive airway pressure settings. Our case highlights the importance of multidisciplinary care in women with congenital central hypoventilation syndrome during pregnancy to optimize pregnancy and fetal outcomes.

UNASSIGNED: Congenital central hypoventilation syndrome (CCHS) is a rare disease characterized by central alveolar hypoventilation and impaired autonomic regulation, caused by pathogenic variants of PHOX2B gene. More than 90% of patients have a polyalanine repeat mutation (PARM) in the heterozygous state, characterized by the expansion of GCN repeats and an increase in the number of alanine repeats, so that genotypes 20/24-20/33 are formed (the normal genotype is 20/20). The remaining 10% of patients harbor non-PARMs.
UNASSIGNED: We present a clinical case of a girl with a novel PHOX2B heterozygous genetic variant in the exon 3: NM_003924.4: c.735_791dup, p.Ala248_Ala266dup. The duplication includes 16 GCN (alanine) repeats and 3 adjacent amino acids. Both clinically healthy parents demonstrated a normal PHOX2B sequence. In addition, the girl has a variant of unknown significance in RYR1 gene and a variant of unknown significance in NKX2-5 gene. The child\'s phenotype is quite special. She needs ventilation during sleep, and has Hirschsprung\'s disease type I, arteriovenous malformation S4 of the left lung, ventricular and atrium septal defects, coronary right ventricular fistula, hemodynamically nonsignificant, episodes of sick sinus and atrioventricular dissociation with bradycardia, divergent alternating strabismus, and oculus uterque (both eyes) (OU) retinal angiopathy. Two episodes of hypoglycemic seizures were also registered. Severe pulmonary hypertension resolved after appropriate ventilation adjustment. Diagnostic odyssey was quite dramatic.
UNASSIGNED: Detection of a novel PHOX2B variant expands the understanding of molecular mechanisms of CCHS and genotype-phenotype correlations.

Congenital central hypoventilation syndrome (CCHS) is an autosomal dominant disorder characterized by alveolar hypoventilation and autonomic dysregulation secondary to mutations of the PHOX2B genes. We present five cases from three generations within the same family with varying degrees of phenotypic expression of the PHOX2B gene mutation. The cases were diagnosed following identification of CCHS in index case at birth. This case series underscores the importance of screening first-degree relatives of individuals with confirmed CCHS and alerts the clinicians to maintain a high degree of suspicion in asymptomatic family members given the high degree of phenotypic variability of CCHS.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is an extremely rare genetic disorder characterized by Autonomic nervous system dysregulation caused by mutations in the PHOX2B gene. Here we introduce the first genetic analysis of a one-month-old CCHS baby girl in Iran.
RESULTS: Genetic analysis of the PHOX2B gene was performed by Sanger sequencing and interpreted using the American College of Medical Genetics and Genomics (ACMG) guideline. The results showed a heterozygous duplication in exon 3, causing a polyalanine repeat expansion mutation to 27 repeats in thePHOX2B gene (20/27 genotype).The patient\'s parents did not demonstrate this mutation on genetic studies.
CONCLUSIONS: According to the ACMG guideline, the mutation is pathogenic, and it was a denovo mutation in the family. The genetic study can help the family for prenatal diagnosis or pre-implantation diagnosis if the parents have gonadal mosaicism.

BACKGROUND: Medulloblastoma is an aggressive brain tumor mostly found in children, few studies on pathogenic germline mutations predisposing this disease was reported.
METHODS: We present an 11-year-old male with medulloblastoma, who harbors a de novo PHOX2B germline mutation as detected by whole exome sequencing (WES). Family history was negative. Sanger sequencing confirmed this mutation in peripheral blood, hair bulbs, urine and saliva. Identification of novel germline mutations is beneficial for childhood cancer screening.
CONCLUSIONS: This case revealed a de novo PHOX2B germline mutation as a potential cause of medulloblastoma in a child and suggests familial germline variant screening is useful when an affected family is considering having a second child.

Congenital central hypoventilation syndrome (CCHS) is caused by the paired-like homeobox 2B (PHOX2B) mutation and predominantly diagnosed during the neonatal period. Although late-onset CCHS and PHOX2B mutation carriers have been reported, the features of these disease states in adults remain uncertain. This study aimed to identify the characteristics of adult-onset CCHS and PHOX2B-mutation carriers in adult.
We mainly searched the PubMed/Medline and Cochrane Databases and classified our target patients into 2 groups: group A, symptomatically diagnosed with late-onset CCHS in adulthood; group B, adult PHOX2B-mutation carriers. Then, clinical characteristics, including the onset, treatment, long-term course, and pattern of the PHOX2B mutation in both groups were analyzed. Additionally, a new adult-case of late-onset CCHS was added to the analysis.
Group A was comprised of 12 patients. The onset triggers of illness included a history of respiratory compromise following general anesthesia and respiratory tract infections. All patients in group A had 20/25 polyalanine repeat mutations and required some chronic ventilatory support at least during sleep, including portable positive pressure ventilator via tracheostomy or noninvasive positive pressure ventilation. In these patients with ventilatory support during sleep, sudden death or poor prognosis was not reported. Group B was comprised of 33 adults from 24 families with PHOX2B mutations. Nine patients in group B were confirmed with the diagnosis of CCHS. Although polyalanine repeat mutations 20/25 represented the most common gene mutation, diverse mutations, including mosaicism, were observed. Hypoventilation of several cases in group B were underdiagnosed by overnight polysomnography without monitoring for CO₂.
Alveolar hypoventilation with unknown origin can be caused by the PHOX2B mutation even in adult cases. Both the identification of the PHOX2B mutation and the incorporation of capnography in polysomnography are important for adult cases with unexplained alveolar hypoventilation or asymptomatic mutation carriers.

Neuroblastoma represents approximately 6 to 10 percent of childhood cancers, yet is one of the most common solid tumors observed in neonates; approximately 700 cases are reported in the United States each year. Neuroblastoma occurs secondary to oncogene mutations that cause abnormal proliferation of neural crest cells and tumor formation anywhere along the spinal cord. Visible manifestations include a blueberry rash and subcutaneous skin nodules. Common histologic findings include multifocal, small, round, blue cell tumors. Cytogenetics testing differentiates aggressive versus nonaggressive forms of neuroblastoma. Treatment ranges from supportive care to surgery and chemotherapy; targeted molecular therapies and immunotherapy offer opportunity to individualize treatment. Morbidity and mortality are contingent upon age at diagnosis and genetic abnormalities. Neonatal clinicians must establish and maintain active knowledge of the current science pertaining to this neoplasm to assist in early identification and timely initiation of medical management. This article presents a case report and comprehensive discussion of the state of the science on metastatic familial (congenital) neuroblastoma.

We describe a three generation family in whom multiple individuals are variably affected due to a PHOX2B non-polyalanine repeat mutation. This family demonstrates extreme phenotypic variability and autosomal dominant transmission over three generations not previously reported in the wider literature. Novel findings also inclue a history of recurrent second trimester miscarriage. Pediatr Pulmonol. 2014; 49:E140-E143. © 2014 Wiley Periodicals, Inc.

Congenital central hypoventilation syndrome (CCHS) is a rare disease characterized by abnormal autonomic control of breathing resulting in hypoventilation. We report an infant girl with CCHS who presented with central sleep apnea, which was first demonstrated by polysomnography when the infant was 5 months old. She was heterozygous for the novel 590delG mutation of PHOX2B, which is classified as a non-polyalanine repeat mutation (NPARM). This mutation is considered to be associated with a relatively mild phenotype.
BACKGROUND: Amimoto Y; Okada K; Nakano H; Sasaki A; Hayasaka K; Odajima H. A case of congenital central hypoventilation syndrome with a novel mutation of the PHOX2B gene presenting as central sleep apnea.