KRIT1 mutations in three Japanese pedigrees with hereditary cavernous malformation

The Genetic Architecture of Vascular Anomalies: Current Data and Future Therapeutic Perspectives Correlated with Molecular Mechanisms

Vascular anomalies (VAs) are morphogenesis defects of the vascular system (arteries, capillaries, veins, lymphatic vessels) singularly or in complex combinations, sometimes with a severe impact on the quality of life. The progress made in recent years with the identification of the key molecular pathways (PI3K/AKT/mTOR and RAS/BRAF/MAPK/ERK) and the gene mutations that lead to the appearance of VAs has allowed the deciphering of their complex genetic architecture. Understanding these mechanisms is critical both for the correct definition of the phenotype and classification of VAs, as well as for the initiation of an optimal therapy and the development of new targeted therapies. The purpose of this review is to present in synthesis the current data related to the genetic factors involved in the etiology of VAs, as well as the possible directions for future research. We analyzed the data from the literature related to VAs, using databases (Google Scholar, PubMed, MEDLINE, OMIM, MedGen, Orphanet) and ClinicalTrials.gov. The obtained results revealed that the phenotypic variability of VAs is correlated with genetic heterogeneity. The identification of new genetic factors and the molecular mechanisms in which they intervene, will allow the development of modern therapies that act targeted as a personalized therapy. We emphasize the importance of the geneticist in the diagnosis and treatment of VAs, as part of a multidisciplinary team involved in the management of VAs.

A Chinese Family With Cerebral Cavernous Malformation Caused by a Frameshift Mutation of the CCM1 Gene: A Case Report and Review of the Literature

Background

Familial cerebral cavernous malformation (FCCM) is a vascular malformation disease closely linked to three identified genes: KRIT1/CCM1, MGC4607/CCM2 and PDCD10/CCM3. Over the past decade, a few cases of cerebral cavernous malformation (CCM) caused by different gene mutations have been reported in Chinese families. Herein, we introduce a Chinese family affected by FCCM due to a kind of KRIT1/CCM1 frameshift mutation. At the same time, a literature review was conducted to identify case reports of familial cerebral cavernous malformation.

Case presentation

The proband in the family in question demonstrated a series of clinical symptoms and features, including headache and bleeding. The proband was hospitalized for headache twice and, both times was examined under suspicion of CCM and received surgical treatment. Magnetic resonance imaging results showed that the proband had multiple intracranial vascular lesions, including on the brain, brainstem, and cerebellum. Genetic test results showed that the classic KRIT1 gene in the proband had a pathogenic mutation. The family members of the proband also showed typical cerebral cavernous malformation when considering clinical manifestations, magnetic resonance imaging findings and genetic test results.

Conclusions

We report a case of Chinese FCCM and its associated symptoms with CCM1-deletion mutations in China. Our findings deepen our understanding of CCM mutations and related phenotypes, the investigation results of this clinical experiment further show that the gene mutation form we reported plays an important role in human FCCM, and this trial investigation is beneficial for genetic counseling for CCM patients.

A comparative analysis of the modified Rankin Scale, Karnofsky Performance Status and Kurtzke expanded disability status scale in the perioperative management of patients with brainstem cavernous malformations

BACKGROUND

The neurological conditions of brainstem cerebral cavernous malformation (BCM) patients are usually ascertained using Karnofsky Performance Status (KPS) or the modified Rankin scale (mRS). However, these scales do not reflect slight changes in brainstem function, because neither KPS nor mRS includes brainstem symptoms such as worsening of swallowing or diplopia. The main problem when managing the BCM patients is that we can neither systematically record neurological changes nor conduct clinical outcome investigations of BCM due to the lack of an adequately detailed assessment system.

PURPOSE

We investigated the usefulness of the Kurtzke expanded disability status scale (EDSS), which is already in widespread clinical use for multiple sclerosis because it provides certainty in evaluating brainstem symptoms.

METHODS

We retrospectively analyzed neurological transitions in surgical BCM cases using the modified Rankin scale (mRS), Karnofsky performance status (KPS), and EDSS. We compared each neurological score transition, and determined which scale allows the most accurate recording of neurological changes in patients.

RESULTS

We proposed lesion removal for patients who showed both neurological deterioration and lesion enlargement caused by re-bleeding, and the surgery was accepted by 10 patients. EDSS allowed us to assess patient status more accurately than KPS or mRS particularly during the perioperative period. In the statistical analysis, only EDSS differed significantly during the period between the initial proposal of surgery and the immediate preoperative period.

CONCLUSION

Our results suggest EDSS to be superior for managing BCM patients, as compared to KPS and mRS. Thus, EDSS may serve as an alternative scale for assessing BCM patients.

Genetic syndromes with vascular malformations - update on molecular background and diagnostics

Vascular malformations are present in a great variety of congenital syndromes, either as the predominant or additional feature. They pose a major challenge to the clinician: due to significant phenotype overlap, a precise diagnosis is often difficult to obtain, some of the malformations carry a risk of life threatening complications and, for many entities, treatment is not well established. To facilitate their recognition and aid in differentiation, we present a selection of notable congenital disorders of vascular system development, distinguishing between the heritable germinal and sporadic somatic mutations as their causes. Clinical features, genetic background and comprehensible description of molecular mechanisms is provided for each entity.