Dominantly inherited cerebral dysplasia: arachnoid cyst associated with mild mental handicap in a mother and her son

Familial and syndromic forms of arachnoid cyst implicate genetic factors in disease pathogenesis

Arachnoid cysts (ACs) are the most common space-occupying lesions in the human brain and present significant challenges for clinical management. While most cases of ACs are sporadic, nearly 40 familial forms have been reported. Moreover, ACs are seen with increased frequency in multiple Mendelian syndromes, including Chudley-McCullough syndrome, acrocallosal syndrome, and autosomal recessive primary ciliary dyskinesia. These findings suggest that genetic factors contribute to AC pathogenesis. However, traditional linkage and segregation approaches have been limited in their ability to identify causative genes for ACs because the disease is genetically heterogeneous and often presents asymptomatically and sporadically. Here, we comprehensively review theories of AC pathogenesis, the genetic evidence for AC formation, and discuss a different approach to AC genomics that could help elucidate this perplexing lesion and shed light on the associated neurodevelopmental phenotypes seen in a significant subset of these patients.

Familial arachnoid cysts: a review of 35 families

INTRODUCTION

Arachnoid cysts are commonly considered congenital lesions, but this has not been proven. With the development of neuroimaging and DNA testing technology, more cases of familial arachnoid cysts have been reported. Herein, we review such cases.

MATERIALS AND METHODS

The PubMed, Embase, and Web of Science databases were searched for case reports of arachnoid cysts published through April 2018. Case reports were included only if two or more related patients were diagnosed with an arachnoid cyst by neuroimaging or intraoperatively. For each report, the following data were extracted: first author name, date of publication, number of families, number of patients, location of the arachnoid cysts, patient age, patient sex, and genetic mutations and associated disease.

RESULTS

Our searches identified 33 case reports involving 35 families and 115 patients. The locations of arachnoid cysts were similar in 25 of the 35 families. Spinal extradural arachnoid cysts were reported most often, followed by arachnoid cysts in the middle fossa and posterior fossa. A left-sided predominance was noticed for arachnoid cysts of the middle fossa. Mutation of the FOXC2 gene was reported most often, and arachnoid cysts may be associated with mutations on chromosome 16.

CONCLUSIONS

Although the origin of arachnoid cysts is believed to have a genetic component by some researchers, the genes associated with arachnoid cysts remain unknown. Unfortunately, the evidence remains insufficient.

Intracranial arachnoid cyst family with autosomal recessive trait mapped to chromosome 6q22.31-23.2

BACKGROUND

Arachnoid cysts are congenital fluid-filled compartments within the cerebrospinal fluid cisterns and cerebral fissures. They most commonly occur sporadically, and familial occurrence has rarely been reported. In this study, we showed the first genetic linkage in the literature in a pure intracranial arachnoid cyst family with autosomal recessive trait.

METHODS

We identified an intracranial arachnoid cyst family in southern Turkey whose six of seven offspring had intracranial arachnoid cysts in different localizations, and collected venous blood from seven offspring of the family. Whole-genome linkage analysis was performed in all offspring.

RESULTS

A theorical maximum logarithm of the odds score of 4.6 was identified at chromosome 6q22.31-23.2. This result shows strong genetic linkage to this locus.

CONCLUSIONS

We present the first genetic linkage analysis result in a pure intracranial arachnoid cyst family in literature. Further investigation of this linkage area can reveal a causative gene causing the intracranial arachnoid cyst phenotype and can illuminate the pathogenesis of this disease.

Neurocognitive and psychological profiles in pediatric arachnoid cyst

OBJECTIVE

This study aims to investigate whether intracranial arachnoid cysts (AC) compromise neurocognitive function and psychological profiles in pediatric patients, depending on various clinical factors.

METHODS

We assessed neurocognitive functions and psychological tests in 35 AC patients and 35 healthy control subjects between October 2007 and April 2008. AC patients ranged in age from 3 to 15 (7.94 +/- 3.12) years old and control patients from 5 to 13 (8.84 +/- 2.17) years old. The location of the AC were temporal (n = 22), frontal (n = 6), suprasellar (n = 4), and posterior fossa (n = 3). Patients underwent neurocognitive and psychological assessments before surgery. To investigate which AC impair neurocognitive function and psychological profile, we assessed intelligence, memory, attention, executive function, behavioral problems, emotional distress, and parenting stress.

RESULTS

AC caused some demonstrated impairment by both neurocognitive function and psychological assessments. Left hemisphere AC tended to have more anxiety; mood changes can be detected depending on cyst grade. An incidental finding of AC after trauma is more intelligent, well-reserved executive function. Frontal locations tended to cause more anxiety than temporal locations.

CONCLUSIONS

Our results imply that intracranial AC impairs some neurocognitive and psychological functions. An incidental finding of AC after trauma was a more intelligent, well-reserved executive function. AC in the left hemisphere, frontal location tended to cause more anxiety. The AC itself did not cause differences in neurocognitive function from the control group. However, parenting stress in the AC group was much higher than in the control group.

Apparently novel genetic syndrome of pachygyria, mental retardation, seizure, and arachnoid cysts

We report on an apparently new syndrome in a consanguineous family with seven members, three of whom have cerebral anomalies including pachygyria and arachnoid cysts along with mental retardation and seizures. The two patients with seizure disorders also had multiple enlarged perivascular spaces seen in the white matter of the centrum semiovale. Our data provide a contribution to the accumulating knowledge on familial cerebral anomalies including arachnoid cysts and lissencephaly. Given the lack of mutation in known lissencephaly genes such as LIS1, 14-3-3epsilon, and DCX, this syndrome may constitute a new phenotype with autosomal recessive inheritance.

Familial arachnoid cysts

Arachnoid cysts are a relatively common incidental finding on neuroimaging studies of the brain. Although most cases are sporadic, there have been some reports of arachnoid cysts in several members of the same family. This report describes two additional families with three members affected in each one. Both families had members with arachnoid cysts in two consecutive generations. In one of the families, arachnoid cysts were associated with a deletion in the long arm of chromosome 16, an association not described previously. These descriptions suggest that in some cases arachnoid cysts may have a genetic basis.

Familial posterior fossa arachnoid cyst

BACKGROUND

Arachnoid cysts are a relatively common incidental finding on CT scans of the brain. They most commonly occur in the middle cranial fossa, where familial occurrence has rarely been reported. Posterior fossa arachnoid cysts are more unusual.

CASE HISTORIES

We report the presence of quadrigeminal cistern arachnoid cysts in siblings.

Familial arachnoid cysts associated with oculopharyngeal muscular dystrophy

Cerebral arachnoid cysts that occur in more than one member of a family have been rarely reported. These familial cases are important because they imply a genetic component in the pathophysiology of these arachnoid cysts. We present an unusual family in which two conditions, a genetic myopathy, oculopharyngeal muscular dystrophy (OPMD), and arachnoid cysts occur together. OPMD is caused by a mutation in the PAPB2 gene that localizes to chromosome 14. In this family, two siblings with genetically confirmed OPMD both have left hemispheric intracranial arachnoid cysts unassociated with other cerebral abnormalities. The association of these two disorders suggests that in this family, a chromosome 14 gene may play a role in the development of arachnoid cysts.