Dural ectasia in individuals with Marfan-like features but exclusion of mutations in the genes FBN1, TGFBR1 and TGFBR2

Spontaneous intracranial hypotension secondary to congenital spinal dural ectasia and genetic mosaicism for tetrasomy 10p: illustrative case

BACKGROUND

Spontaneous intracranial hypotension has historically been a poorly understood pathology that is often unrecognized and undertreated. Even more rarely has it been described in pediatric patients with an otherwise benign past medical history.

OBSERVATIONS

Herein the authors describe one of the youngest patients ever reported, a 2-year-old girl who developed severe headaches, nausea, and vomiting and experienced headache relief after lying down. Imaging revealed tonsillar herniation 14 mm below the foramen magnum, presumed to be a Chiari malformation, along with extensive dural cysts starting from thoracic level T2 down to the sacrum. She was found to have streaky skin pigmentary variation starting from the trunk down to her feet. Genetic analysis of skin biopsies revealed mosaicism for an isodicentric marker chromosome (10p15.3–10q11.2 tetrasomy) in 27%–50% of cells. After undergoing a suboccipital and cervical decompression at an outside institution, she continued to be symptomatic. She was referred to the authors’ hospital, where she was diagnosed with spontaneous intracranial hypotension.

LESSONS

After receiving a series of epidural blood patches, the patient experienced almost complete relief of her symptoms. To the authors’ knowledge, this is the first time this chromosomal anomaly has ever been reported in a living child, and this may represent a new genetic association with dural ectasia.

Sex- and Age-Related Differences in the Clinical and Neuroimaging Characteristics of Patients With Spontaneous Intracranial Hypotension: A Records Review

BACKGROUND

The significance of sex- and age-related differences in the clinical course of spontaneous intracranial hypotension (SIH) was investigated.

METHODS

We retrospectively studied 40 consecutive patients (female:male = 28:12, median age 41.5 years) treated under clinical diagnoses of SIH satisfying the International Classification of Headache Disorders 3rd edition criteria, including 37 patients (92.5%) with diffuse pachymeningeal enhancement. The patients were divided into two groups by age and sex, and the clinical and neuroimaging findings in each group were investigated.

RESULTS

Acute onset (female:male = 82.1%:50.0%, P = .042), severe headache (75.0%:41.7%, P = .045) occurred with higher frequency in females than in males, and SDH occurred with lower frequency in females than in males (28.6%:75.0%, P = .006). Duration until the consultation (2:14 days, P = .022), SDH thickness (0:7.1 mm, P = .001), and iter displacement (1.6:7.1 mm, P = .004) was greater in males. Acute onset (Younger [≤40 years]: older [>40 years] = 94.1%:56.5%, P = .012), occurred with higher frequency in younger patients, and duration until the consultation (1:5 days, P = .001), frequency of SDH (17.7%:60.9%, P = .010), SDH thickness (0:5.9 mm, P = .003), in older patients. All nine patients with thunderclap headache were female, with median age of 37 years.

CONCLUSIONS

More severe clinical symptoms with acute onset were observed in females and younger patients of SIH. Comparatively rare subdural hygroma/hematoma on magnetic resonance imaging might result from the shorter duration to diagnosis in females and younger patients.

KEY WORDS

spontaneous intracranial hypotension, sex, age, magnetic resonance imaging, thunderclap headache.

Marfan syndrome: current perspectives

Marfan syndrome (MFS) is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, due to mutations in the FBN1 gene encoding fibrillin 1. It is an important protein of the extracellular matrix that contributes to the final structure of a microfibril. Few cases displaying an autosomal recessive transmission are reported in the world. The FBN1 gene, which is made of 66 exons, is located on chromosome 15q21.1. This review, after an introduction on the clinical manifestations that leads to the diagnosis of MFS, focuses on cardiovascular manifestations, pharmacological and surgical therapies of thoracic aortic aneurysm and/or dissection (TAAD), mechanisms underlying the progression of aneurysm or of acute dissection, and biomarkers associated with progression of TAADs. A Dutch group compared treatment with losartan, an angiotensin II receptor-1 blocker, vs no other additional treatment (COMPARE clinical trial). They observed that losartan reduces the aortic dilatation rate in patients with Marfan syndrome. Later on, they also reported that losartan exerts a beneficial effect on patients with Marfan syndrome carrying an FBN1 mutation that causes haploinsufficiency (quantitative mutation), while it has no significant effect on patients displaying dominant negative (qualitative) mutations. Moreover, a French group in a 3-year trial compared the administration of losartan vs placebo in patients with Marfan syndrome under treatment with beta-receptor blockers. They observed that losartan decreases blood pressure but has no effect on aortic diameter progression. Thus, beta-receptor blockers remain the gold standard therapy in patients with Marfan syndrome. Three potential biochemical markers are mentioned in this review: total homocysteine, serum transforming growth factor beta, and lysyl oxidase. Moreover, markers of oxidative stress measured in plasma, previously correlated with clinical features of Marfan syndrome, may be explored as potential biomarkers of clinical severity.

Truncating mutations in the last exon of NOTCH3 cause lateral meningocele syndrome

Lateral meningocele syndrome (LMS, OMIM%130720), also known as Lehman syndrome, is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction. The characteristic lateral meningoceles represent the severe end of the dural ectasia spectrum and are typically most severe in the lower spine. Facial features of LMS include hypertelorism and telecanthus, high arched eyebrows, ptosis, midfacial hypoplasia, micrognathia, high and narrow palate, low-set ears and a hypotonic appearance. Hyperextensibility, hernias and scoliosis reflect a connective tissue abnormality, and aortic dilation, a high-pitched nasal voice, wormian bones and osteolysis may be present. Lateral meningocele syndrome has phenotypic overlap with Hajdu-Cheney syndrome. We performed exome resequencing in five unrelated individuals with LMS and identified heterozygous truncating NOTCH3 mutations. In an additional unrelated individual Sanger sequencing revealed a deleterious variant in the same exon 33. In total, five novel de novo NOTCH3 mutations were identified in six unrelated patients. One had a 26 bp deletion (c.6461_6486del, p.G2154fsTer78), two carried the same single base pair insertion (c.6692_93insC, p.P2231fsTer11), and three individuals had a nonsense point mutation at c.6247A > T (pK2083*), c.6663C > G (p.Y2221*) or c.6732C > A, (p.Y2244*). All mutations cluster into the last coding exon, resulting in premature termination of the protein and truncation of the negative regulatory proline-glutamate-serine-threonine rich PEST domain. Our results suggest that mutant mRNA products escape nonsense mediated decay. The truncated NOTCH3 may cause gain-of-function through decreased clearance of the active intracellular product, resembling NOTCH2 mutations in the clinically related Hajdu-Cheney syndrome and contrasting the NOTCH3 missense mutations causing CADASIL.

Standardization and validation of a novel and simple method to assess lumbar dural sac size

AIM

To develop and validate a simple, reproducible method to assess dural sac size using standard imaging technology.

MATERIALS AND METHODS

This study was institutional review board-approved. Two readers, blinded to the diagnoses, measured anterior–posterior (AP) and transverse (TR) dural sac diameter (DSD), and AP vertebral body diameter (VBD) of the lumbar vertebrae using MRI images from 53 control patients with pre-existing MRI examinations, 19 prospectively MRI-imaged healthy controls, and 24 patients with Marfan syndrome with prior MRI or CT lumbar spine imaging. Statistical analysis utilized linear and logistic regression, Pearson correlation, and receiver operating characteristic (ROC) curves.

RESULTS

AP-DSD and TR-DSD measurements were reproducible between two readers (r = 0.91 and 0.87, respectively). DSD (L1–L5) was not different between male and female controls in the AP or TR plane (p = 0.43; p = 0.40, respectively), and did not vary by age (p = 0.62; p = 0.25) or height (p = 0.64; p = 0.32). AP-VBD was greater in males versus females (p = 1.5 × 10⁻⁸), resulting in a smaller dural sac ratio (DSR) (DSD/VBD) in males (p = 5.8 × 10⁻⁶). Marfan patients had larger AP-DSDs and TR-DSDs than controls (p = 5.9 × 10⁻⁹; p = 6.5 × 10⁻⁹, respectively). Compared to DSR, AP-DSD and TR-DSD better discriminate Marfan from control subjects based on area under the curve (AUC) values from unadjusted ROCs (AP-DSD p < 0.01; TR-DSD p = 0.04).

CONCLUSION

Individual vertebrae and L1–L5 (average) AP-DSD and TR-DSD measurements are simple, reliable, and reproducible for quantitating dural sac size without needing to control for gender, age, or height.

Noninvasive diagnosis and management of spontaneous intracranial hypotension in patients with marfan syndrome: Case Report and Review of the Literature

Background:

Spontaneous intracranial hypotension is an uncommon clinical entity. Heritable connective tissue disorders (HCTD), such as Marfan syndrome, are frequently implicated as an underlying cause, due to dural structural weaknesses that predispose patients to spontaneous cerebrospinal fluid (CSF) leak. Due to the high prevalence of multi-system disease in HCTD, diagnosis and treatment are often complicated.

Case Description:

We present a 58-year-old female with Marfan syndrome on anticoagulation for a mechanical aortic valve replacement who came to medical attention with severe, acute-onset headache following a straining episode. Noninvasive magnetic resonance (MR) myelography confirmed thoracic CSF extravasations and multiple lumbar diverticula. The patient was treated conservatively and her symptoms resolved.

Conclusion:

We discuss the common presentation, diagnostic tools, and treatment options for spontaneous CSF leaks in patients with Marfan syndrome or related HCTD with an emphasis on noninvasive modalities and a review of the major radiographic criteria used to diagnose dural abnormalities, such as dural ectasia.

Dural ectasia in Loeys-Dietz syndrome: comprehensive study of 30 patients with a TGFBR1 or TGFBR2 mutation

The purpose of this study was to assess the frequency, severity, and clinical associations of dural ectasia (DE) in Loeys-Dietz syndrome (LDS). Database analysis of three German metropolitan regions identified 30 patients with LDS and TGFBR1 mutation in 6 and a TGFBR2 mutation in 24 individuals (17 men; mean age: 31 ± 19 years), as well as 60 age and sex-matched control patients with Marfan syndrome carrying a FBN1 mutation. DE was present in 22 patients with LDS (73%), and it related to skeletal score points (p = 0.008), non-skeletal score points (p < 0.001), and to the presence of ≥7 systemic score points (p = 0.010). Similarly, the severity of DE was related to body height (p = 0.010) and non-skeletal score points (p = 0.004). Frequency (p = 0.131) and severity of DE (p = 0.567) was similar in LDS and Marfan syndrome. DE is a manifestation of LDS that occurs with similar frequency and severity as in Marfan syndrome. Severity of DE may serve as a marker of the overall connective tissue disease severity. LDS may be considered in patients with DE.

Late diagnosis of lateral meningocele syndrome in a 55-year-old woman with symptoms of joint instability and chronic musculoskeletal pain

Lateral meningocele syndrome (LMS) is a rare hereditary connective tissue disorder characterized by pan-spinal meningoceles, specific facial dysmorphism, skeletal and soft tissue abnormalities, and hypotonia and/or muscle weakness. LMS has been observed in eleven patients with two instances of vertical transmission, and seven sporadic cases with an age at diagnosis ranging from 25 months to 33 years. We report on a further observation of LMS in a 55-year-old woman presenting with a long history of joint instability, chronic musculoskeletal pain, and iatrogenic bladder and anorectal dysfunction due to irreversible nerve damage after surgical excision of a meningeal cyst. Her clinical characteristics are compared with those of previously reported patients, as well as two further cases originally diagnosed with Hajdu-Cheney and Ehlers-Danlos syndromes, but displaying typical features of LMS.

Comprehensive analysis of dural ectasia in 150 patients with a causative FBN1 mutation

The purpose of this study was to perform a comprehensive study of dural ectasia (DE) related to FBN1 mutations. We performed a database analysis of two German metropolitan regions of 150 patients (68 men, 82 women; mean age 35 ± 16 years). All patients had a FBN1 mutation and underwent dural magnetic resonance imaging. Age was <16 years in 20, 16-25 in 27, 26-35 in 67, and >35 in 36 patients. Prevalence of dural ectasia was 89% with criteria of Oosterhof and Habermann, 83% with Fattori, 78% with Lundby, and 59% with Ahn. DE was less frequent in patients <16 years with Ahn and Fattori. DE related to skeletal manifestations with all criteria, to aortic Z-scores and mitral valve prolapse with criteria of Habermann and Lundby, and to age with criteria of Fattori. The Fattori-grade of DE increased with age, aortic Z-scores, and skeletal score points. There was no consistent relationship of DE with any type of FBN1 mutation. DE is frequent in patients with FBN1 mutations irrespective of age and its severity increases during life. Criteria of Oosterhof and Habermann yielded most consistent diagnostic results. DE relates to skeletal involvement, aortic Z-scores, and mitral valve prolapse.

Marfan syndrome and symptomatic sacral cyst: report of two cases

CONTEXT

Meningeal abnormalities such as dural ectasia are seen in Marfan syndrome, but spinal meningeal cysts are rarely seen. These cysts usually asymptomatic and often found incidentally on magnetic resonance imaging, large cysts may cause neurological deficits and pain secondary to nerve root compression.

DESIGN

Case reports.

FINDINGS

Two patients with Marfan syndrome presented with urinary symptoms secondary to dural ectasia and sacral cysts. Patient 1 had a history of low back pain, erectile dysfunction, and occasional urinary incontinence and groin pain with recent symptom worsening. He underwent L5 partial laminectomy and S1-S2 laminectomy with sacral cyst decompression. Nine weeks later, he underwent drainage of a sacral pseudomeningocele. Pain and urinary symptoms resolved, and he remains neurologically normal 2 years after surgery. Patient 2 presented after a fall on his tailbone, complaining of low back pain and difficulty urinating. Physical therapy was implemented, but after 4 weeks, urinary retention had not improved. He then underwent resection of the sacral cyst and S1-S3 laminectomy. Pain and paresthesias resolved and bowel function returned to normal. Other than needing intermittent self-catheterization, all other neurologic findings were normal 30 months after surgery.

CONCLUSION/CLINICAL RELEVANCE

Surgical goals for sacral cysts include resection as well as closure of the dura, which can be challenging due to thinning from ectasia. Neurosurgical intervention in Marfan syndrome is associated with a high risk of dural tears and osseous complications, and should be performed only when symptoms are severe.

Focal dermal hypoplasia (Goltz-Gorlin syndrome): a new case with a novel variant in the PORCN gene (c.1250T>C:p.F417S) and unusual spinal anomaly

Focal dermal hypoplasia (FDH; Goltz-Gorlin syndrome; OMIM 305600) is a disorder that features involvement of the skin, skeletal system, and eyes. It is caused by loss-of-function mutations in the PORCN gene. We report a young girl with FDH, microphthalmos associated with colobomatous orbital cyst, dural ectasia and cystic malformation of the spinal cord, and a de novo variant in PORCN. This association has not been previously reported, and based on these observations the phenotypic spectrum of FDH might be broader than previously appreciated. It would be prudent to alter the suggested surveillance for this rare disorder.

Dural ectasia and FBN1 mutation screening of 40 patients with Marfan syndrome and related disorders: role of dural ectasia for the diagnosis

Marfan syndrome is an autosomal dominant disorder of connective tissue caused by mutations in the gene encoding fibrillin-1 (FBN1), a matrix component of microfibrils. Dural ectasia, i.e. enlargement of the neural canal mainly located in the lower lumbar and sacral region, frequently occurs in Marfan patients. The aim of our study was to investigate the role of dural ectasia in raising the diagnosis of Marfan syndrome and its association with FBN1 mutations. We studied 40 unrelated patients suspected for MFS, who underwent magnetic resonance imaging searching for dural ectasia. In all of them FBN1 gene analysis was also performed. Thirty-seven patients resulted affected by Marfan syndrome according to the '96 Ghent criteria; in 30 of them the diagnosis was confirmed when revaluated by the recently revised criteria (2010). Thirty-six patients resulted positive for dural ectasia. The degree of dural ectasia was grade 1 in 19 patients, grade 2 in 11 patients, and grade 3 in 6 patients. In 7 (24%) patients, the presence of dural ectasia allowed to reach a positive score for systemic feature criterion. Twenty-four patients carried an FBN1 mutation, that were represented by 13 missense (54%), and 11 (46%) mutations generating a premature termination codon (PTC, frameshifts and stop codons). No mutation was detected in the remaining 16 (6 patients with MFS and 10 with related disorders according to revised Ghent criteria). The prevalence of severe (grade 2 and grade 3) involvement of dura mater was higher in patients harbouring premature termination codon (PTC) mutations than those carrying missense-mutations (8/11 vs 2/13, P = 0.0111). Our data emphasizes the importance of dural ectasia screening to reach the diagnosis of Marfan syndrome especially when it is uncertain and indicates an association between PTC mutations and severe dural ectasia in Marfan patients.

A simple clinical model to estimate the probability of Marfan syndrome

BACKGROUND

Marfan syndrome is a heritable connective tissue disease. Definitive diagnosis is complex, and requires sequencing of a large gene, FBN1.

AIM

We aimed to develop a simple model to estimate the pre-test probability of Marfan syndrome.

DESIGN

Prospective cross-sectional study.

METHODS

We applied diagnostic standards for definitive diagnosis or exclusion of Marfan syndrome in 329 consecutive persons. In 208 persons with random assignment to our derivation group, we performed multivariate logistic regression to assess 14 clinical variables for inclusion in a prediction model with derivation of score points from the estimated coefficients. We created cut-offs to classify low, moderate and high probability of Marfan syndrome. For validation, we applied the model to the remaining 121 persons.

RESULTS

We identified seven variables for inclusion in the final model, where we assigned four score points to ectopia lentis, two points to a family history of Marfan syndrome, and one point to previous thoracic aortic surgery, to pectus excavatum, to a wrist and thumb sign, to previous pneumothorax, and to skin striae. In the derivation group 12, 42 and 92% of persons with low (≤1 point), moderate (>1-3.5 points) or high pre-test probability (>3.5 points) had Marfan syndrome, compared to 12, 57 and 91%, respectively, in the validation group. Positive likelihood ratios were 13.96 and 8.54 in the high probability group of the derivation and validation group, respectively.

CONCLUSION

A simple prediction model provides evidence for Marfan syndrome. This model can be used to identify patients who require definitive diagnostic work-up.

Analysis of phenotype and genotype information for the diagnosis of Marfan syndrome

Marfan syndrome is considered a clinical diagnosis. Three diagnostic classifications comprising first, Marfan genotype with a causative FBN1 gene mutation; second, Marfan phenotype with clinical criteria of the original Ghent nosology (Ghent-1); and third, phenotype with clinical criteria of its current revision (Ghent-2) in 300 consecutive persons referred for confirmation or exclusion of Marfan syndrome (150 men, 150 women aged 35 ± 13 years) were used. Sequencing of TGBR1/2 genes was performed in 128 persons without FBN1 mutation. Marfan genotype was present in 140, Ghent-1 phenotype in 139, and Ghent-2 phenotype in 124 of 300 study patients. Marfan syndrome was confirmed in 94 and excluded in 129 persons consistently by all classifications, but classifications were discordant in 77 persons. With combined genotype and phenotype information confirmation of Marfan syndrome was finally achieved in 126 persons by Ghent-1 and in 125 persons by Ghent-2 among 140 persons with Marfan genotype, and exclusion was accomplished in 139 persons by Ghent-1 and in 141 persons by Ghent-2 among 160 persons without Marfan genotype. In total, genotype information changed final diagnoses in 22 persons with Ghent-1, and in 32 persons with Ghent-2. It is concluded that genotype information is essential for diagnosis or exclusion of Marfan syndrome.