X Chromosome-Inactivation Patterns in 31 Individuals with PHACE Syndrome

Prevalence and Complications of Aberrant Subclavian Artery in Patients With Heritable and Nonheritable Arteriopathies

BACKGROUND

An aberrant subclavian artery (ASA) (or lusoria) is the most common congenital anomaly of the aortic arch (0.5%-2.2%; female-to-male ratio 2:1 to 3:1). ASA can become aneurysmal and result in dissection, involving Kommerell's diverticulum when present and the aorta. Data of its significance in genetic arteriopathies are not available.

OBJECTIVES

The purpose of this study was to assess the prevalence and complications of ASA in gene-positive and -negative nonatherosclerotic arteriopathies.

MATERIALS

The series includes 1,418 consecutive patients with gene-positive (n = 854) and gene-negative arteriopathies (n = 564) diagnosed as part of institutional work-up for nonatherosclerotic syndromic and nonsyndromic arteriopathies. Comprehensive evaluation includes genetic counseling, next-generation sequencing multigene testing, cardiovascular and multidisciplinary assessment, and whole-body computed tomography angiography.

RESULTS

ASA was found in 34 of 1,418 cases (2.4%), with a similar prevalence in gene-positive (n = 21 of 854, 2.5%) and gene-negative (n = 13 of 564, 2.3%) arteriopathies. Of the former 21 patients, 14 had Marfan syndrome, 5 had Loeys-Dietz syndrome, 1 had type-IV Ehlers-Danlos syndrome, and 1 had periventricular heterotopia type 1. ASA did not segregate with genetic defects. Dissection occurred in 5 of 21 patients with genetic arteriopathies (23.8%; 2 Marfan syndrome and 3 Loeys-Dietz syndrome), all with associated Kommerell's diverticulum. No dissections occurred in gene-negative patients. At baseline, none of the 5 patients with ASA dissection fulfilled criteria for elective repair according to guidelines.

CONCLUSIONS

The risk of complications of ASA is higher in patients with genetic arteriopathies and is difficult to predict. In these diseases, imaging of the supra-aortic trunks should enter baseline investigations. Determination of precise indications for repair can prevent unexpected acute events such as those described.

Molecular Pathways and Possible Therapies for Head and Neck Vascular Anomalies

Vascular Anomalies are a heterogenous group of vascular lesions that can be divided, according to the International Society for the Study of Vascular Anomalies Classification, into two main groups : Vascular Tumors and Vascular Malformations. Vascular Malformations can be further subdivided into slow-flow and fast-flow malformations. This clinical and radiological classification allows for a better understanding of vascular anomalies and aims to offer a more precise final diagnosis. Correct diagnosis is essential to propose the best treatment, which traditionally consists of surgery, embolization or sclerotherapy. Since a few years, medical treatment has become an important part of multidisciplinary treatment. Genetic and molecular knowledge of vascular anomalies are increasing rapidly and opens the door for a molecular classification of vascular anomalies according to the underlying pathways involved. The main pathways seem to be: PI3K/AKT/mTOR (PIKopathies) and RAS/RAF/MEK/ERK (RASopathies). Knowing the underlying molecular cascades allows us to use targeted medical therapies. The first part of this article aims to review the vascular anomalies seen in the head and neck region and their underlying molecular causes and involved pathways. The second part will propose an overview of the available targeted therapies based on the affected molecular cascade. This article summarizes theragnostic treatments available in vascular anomalies.

PHACE Syndrome Presenting With Retinal Degeneration, Cortical Dysplasia, Microphthalmia, and Atrial Septal Defect in a South Asian Boy

PHACE syndrome is a rare disorder of vasculogenesis that occurs during the first trimester of pregnancy. The disorder commonly presents with posterior fossa brain anomalies and coarctation of aorta/arterial anomalies and is predominantly seen in female patients. Herein, we report a male child with PHACE syndrome who had several less common features such as cortical dysplasia, retinal degeneration, and microphthalmia. The diagnosis of PHACE syndrome was confirmed based on revised diagnostic criteria and by the presence of one major criterion and two minor criteria in addition to >5 cm haemangioma. Further, the reported child had atrial septal defect as the only cardiac abnormality, and this has been rarely described in patients with PHACE syndrome.

Epidemiology, Clinical Features, and Use of Early Supportive Measures in PHACE Syndrome: A European Multinational Observational Study

BACKGROUND

PHACE syndrome is a rare inborn condition characterized by large facial hemangiomas and variable malformations of the arterial system, heart, central nervous system, and eyes. According to Orphanet estimates, the prevalence is <1.0 per million. Data from Europe are limited to small case series, and there are no population-based data available.

OBJECTIVES

We conducted the present study to provide population-based estimates of the disease prevalence of PHACE syndrome in children in Germany, Switzerland, and Austria. We compared these first systematic data on PHACE syndrome from Europe to published data from the PHACE Syndrome International Clinical Registry and Genetic Repository (USA). Clinical features in our cohort with PHACE syndrome were assessed in detail, including the need for early supportive measures.

METHODS

We used a population-based approach by means of a previously well-established network of child neurologists from Germany, Switzerland, and Austria ("ESNEK") to identify potential patients. The patients' guardians and child neurologists were asked to fill in questionnaires developed in collaboration with the International PHACE Registry.

RESULTS

We identified 19 patients with PHACE syndrome. Estimated prevalence rates were 6.5 per million in Switzerland, 0.59 per million in Germany, and 0.65 per million in Austria. A subset of 10 patients from Germany and Switzerland participated in our study, providing detailed clinical assessment (median age: 2.5 years; 9 females, 1 male). Cerebrovascular involvement was frequent (80%). Facial hemangioma extent correlated significantly with the number of organs involved (p = 0.011). In 9 out of 10 patients, facial hemangiomas were treated successfully with oral propranolol. Baseline demographic data as well as the rate of cerebrovascular and cardiovascular anomalies were in line with those from the US International PHACE Registry and other published PHACE cohorts.

CONCLUSIONS

Our study provides population-based estimates for PHACE syndrome in 3 German-speaking countries. The data from Switzerland indicate that PHACE syndrome may be more prevalent than demonstrated by previous reports. Underreporting of PHACE syndrome in Germany and Austria likely accounts for the differences in prevalence rates. The clinical observation of a potential association between the size of facial hemangioma and extent of organ involvement warrants further investigation.

PHACE syndrome: Infantile hemangiomas associated with multiple congenital anomalies: Clues to the cause

Infantile hemangiomas (IH) are the most common vascular tumor of infancy with an estimated 80,000 annual diagnoses in the United States. The genetic mechanisms underlying IH and the related multi-organ birth defect syndromes, PHACE (an acronym for Posterior fossa brain malformations, segmental facial Hemangiomas, Arterial anomalies, Cardiac defects, Eye anomalies, and sternal clefting or supraumbilical raphe) and LUMBAR (an acronym for Lower body hemangiomas, Urogenital anomalies, Myelopathy, Bone deformities, Anorectal malformations/Arterial anomalies, Renal anomalies) remain unsolved. With advances in next generation sequencing (NGS), genomic alterations have been identified in a wide range of vascular anomaly syndromes. We hypothesize that PHACE is a genetic disorder, caused by somatic mutations, likely in cancer genetic pathways. Identification of the genetic etiology will lead to improved diagnosis in PHACE syndrome and development of targeted therapies for IH and related congenital anomalies.

Transient ischemic attack in elderly patient with PHACE syndrome

Background:

Posterior fossa brain malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, and eye abnormalities (PHACE) is a rare congenital anomaly with a broad spectrum of clinical manifestations.

Case Description:

We describe a 75-year-old male with PHACE anomaly, aortic anomaly, malformation of brain, aplastic right carotid artery, and cervical vasculopathy. He presented with a transient ischemic attack with the left hemiparesis, a rare clinical presentation of the PHACE syndrome. He had an uneventful recovery and recently completed a 2-year follow-up after the superficial temporal artery to middle cerebral artery anastomosis.

Conclusion:

PHACE syndrome should be kept in mind, even in individuals of advanced age, in the instance of a TIA, especially in situations which may involve induced hypoperfusion.

Distal aortic arch aneurysm in an adult case of PHACE syndrome

A rare case of adult PHACE syndrome with a distal aortic arch aneurysm was treated surgically. The patient had several anomalies including uneven cerebral blood flow, a small left common carotid artery and a narrowed transverse aorta. Under deep hypothermic circulatory arrest, aortic replacement with reconstruction of the left subclavian artery was performed uneventfully. Cystic degeneration of the tunica media was observed in the aneurysm wall.

Skewed X-chromosome inactivation and next-generation sequencing to identify a novel SMPX variants associated with X-linked hearing loss in a Chinese family

OBJECTIVE

Hereditary nonsyndromic hearing loss is extremely heterogeneous and an X-linked form accounts for 1-5% of all cases. The aim of this study was to identify the pathogenic variants in a nonsyndromic X-linked dominant hearing loss family, and explain the reason of different hearing phenotype in hearing between the two sisters with the same variant.

METHODS

Targeted gene capture and next-generation sequencing were used to study the genetic cause. What's more, methylation differences among the androgen receptor genes were used to investigate whether the different hearing levels of the two sisters is related to X-chromosome inactivation (Xi).

RESULTS

We identified SMPX c.29insA (p.Asn10Lysfs*3) as the novel variant causing deafness. The skewed X-chromosome inactivation was relevant to the hearing difference between the two sisters.

CONCLUSION

Targeted gene capture and NGS is an efficient way to identify pathogenic variants in genes. Analysis of X-chromosome inactivation is beneficial to the diagnosis and genetic counseling of X-linked dominant hearing loss families.

[Research progresses in the pathogenesis, diagnosis and treatment of infantile hemangioma with PHACE syndrome]

Infant hemangioma, the most common benign tumor in children, is characterized by rapid proliferation, followed by slower spontaneous involution. However, some patients with facial segmental hemangioma are associated with PHACE syndrome. PHACE syndrome is characterized by vascular nerve and vascular cutaneous lesions of multiple systemic systems, often resulting in structural and functional impairments. Recent studies have demonstrated that the possible pathogeneses of PHACE syndrome mainly include hypoxia, abnormality of mesodermal vascular endothelial cells, genetic abnormality, and abnormality of interstitial mesenchymal stem cells. The current medications for hemangioma with PHACE syndrome include beta blockers, glucocorticoids, and mTOR inhibitors. This review article mainly describes the pathogenesis, diagnoses and treatments of PHACE syndrome, in order to provide directions for diagnosis and treatment of this disorder.

Structural malformations of the brain, eye, and pituitary gland in PHACE syndrome

PHACE syndrome is the association of segmental facial hemangiomas with congenital arterial, brain, cardiac, and ocular anomalies. Structural brain malformations affect 41-52% of PHACE patients and can be associated with focal neurologic deficits, developmental delays, and/or intellectual disability. To better characterize the spectrum of structural brain and other intracranial anomalies in PHACE syndrome, MRI scans of the head/neck were retrospectively reviewed in 55 patients from the PHACE Syndrome International Clinical Registry and Genetic Repository. All registry patients with a diagnosis of definite PHACE syndrome who had MRI scans of satisfactory quality were included. Of 55 patients, 34 (62%) demonstrated ≥1 non-vascular intracranial anomaly; structural brain malformations were present in 19 (35%). There was no difference in the prevalence of brain anomalies between genders. Brain anomalies were more likely in patients with S1 and/or S2 distribution of facial hemangioma. The most common structural brain defects were cerebellar hypoplasia (25%) and fourth ventricle abnormalities (13%). Dandy-Walker complex and malformations of cortical development were present in 9% and 7%, respectively. Extra-axial findings such as pituitary anomalies (18%) and intracranial hemangiomas (18%) were also observed. Six patients (11%) had anomalies of the globes or optic nerve/chiasm detectable on MRI. Brain malformations comprise a diverse group of structural developmental anomalies that are common in patients with PHACE syndrome. Along with brain malformations, numerous abnormalities of the pituitary, meninges, and globes were observed, highlighting the need for careful radiologic assessment of these structures in the neuroimaging workup for PHACE syndrome.

Prenatal Risk Factors for PHACE Syndrome: A Study Using the PHACE Syndrome International Clinical Registry and Genetic Repository

The cause of PHACE syndrome is unknown. In a study of 218 patients, we examined potential prenatal risk factors for PHACE syndrome. Rates of pre-eclampsia and placenta previa in affected individuals were significantly greater than in the general population. No significant risk factor differences were detected between male and female subjects.