Causes of death in patients with tuberous sclerosis

The value of renal scintigraphy in the conservative management of a patient with tuberous sclerosis

The diagnostic dilemma to differentiate angiomyolipomas from renal cell carcinoma has been resolved by computerized tomography and sonography. However, these imaging modalities are incapable of estimating the functional contribution of individual kidneys. Renal scintigraphy can be used for a quantitative impression of renal function and is, therefore, of additional value in monitoring conservatively treated tuberous sclerosis patients as shown by the case report.

Tuberous sclerosis complex: neonatal deaths in three of four children of consanguineous, non-expressing parents

We describe here four sibs, born to consanguineous, healthy, asymptomatic parents. Three of these infants had a rapidly fatal course in the neonatal period; death was attributed to congestive heart failure with radiographic evidence of cardiomegaly in all of them. Necropsy was done in only one of them and showed the typical findings of tuberous sclerosis complex (TSC) in the central nervous system (CNS), kidneys, heart, and liver. The fourth sib, currently 2 years old, also has typical signs of TSC, namely hypomelanotic skin macules and calcified subependymal nodules. Both parents and a living maternal grandmother had appropriate examination, which included skin inspection under Wood's lamp, dental examination, fundoscopy, echocardiography, abdominal and renal ultrasound, and head CT and MRI scans, and no signs of TSC were found in either parent or in the only living grandmother. By history alone there is no other relative with signs or symptoms suggestive of TSC. Linkage analysis and loss of heterozygosity (LOH) investigations on a variety of lesions obtained from postmortem and tissue or blood specimens from all available family members studied failed to identify a microdeletion in the chromosomal regions where TSC genes are located. It is very unusual that in a single TSC family there were three consecutive neonatal deaths, and very likely that all had cardiac rhabdomyomas. Moreover, to the best of our knowledge, there are no previous reports of TSC families with more than one affected sib, unusually severe manifestations of the disease, and completely normal, consanguineous parents.

Mutations and polymorphisms in the tuberous sclerosis complex gene on chromosome 16

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder of benign tumor formation, hamartomata, and hamartias. TSC has been shown to be genetically heterogeneous, with one causative gene mapping to chromosome 9q (denoted TSC1) and at least one other gene on chromosome 16p (denoted TSC2). The TSC2 gene was recently cloned. We have tested 88 TSC probands with the TSC2 cDNA by Southern blotting searching for gross deletions/rearrangements/insertions. We detected two deletions and a rare intragenic polymorphic variant. This is a similar rate of mutation detection (2/88; 2.3%) to that in the original report (10/260/; 3.8%). The rare polymorphic variant was initially detected in the proband of a chromosome 9-linked multiplex TSC family. The polymorphism segregated with previously tested markers on chromosome 16 independently of the disease gene, verifying that the variation was unrelated to TSC status. We have also begun searching for subtle mutations by SSCA and direct sequencing. After screening three exons, we found two intragenic polymorphic variants. Both polymorphisms are common, making them useful for linkage studies in known affected families.

Renal manifestations of tuberous sclerosis complex

Patients with tuberous sclerosis complex (TSC) are at increased risk of renal disease, predominantly angiomyolipomas and renal cysts. We retrospectively reviewed clinical data of 71 patients diagnosed with TSC. Progression of renal lesions was noted. TSC patients with renal lesions were compared with TSC patients without renal disease. Fifteen of 38 patients had renal abnormalities by imaging at presentation. Six of 9 with initially normal kidneys subsequently developed new lesions. Although not of statistical significance, there was a trend toward increased retinal hamartomas, cardiac rhabdomyomas, and skin lesions in those patients who also had renal abnormalities. Renal disease should be considered and sought in all patients with TSC, both at initial presentation and subsequently, since renal disease is a very significant cause of morbidity and mortality.

Treatment of the facial angiofibromas of tuberous sclerosis

Tuberous sclerosis is an inherited syndrome with mental retardation, epilepsy, and acne rosacea being the classic triad of manifestations. The facial skin problems can present a cosmetic deformity or, as in the three patients presented here, can produce difficulties with hygiene and nasal breathing. Various approaches to treatment have been described over the last century, but no long-term results have been presented. Because of the full-thickness skin involvement, complete removal is not practical, and treatment should be directed toward acceptable long-term results with minimal surgical morbidity. Shaving and dermabrasion of the involved area produce very satisfactory results, but long-term follow-up of approximately 10 years reveals that there is a variable amount of recurrence and that subsequent treatment will be required.

The natural history of cardiac rhabdomyoma with and without tuberous sclerosis

The aim of the present study is to contribute to the knowledge of the natural history of cardiac rhabdomyoma in children with and without tuberous sclerosis. In a retrospective study, 33 children with cardiac rhabdomyoma were collected from three pediatric cardiology centres. In 30/33 patients tuberous sclerosis was associated. High prevalence of cardiac rhabdomyoma was found in infancy, with 21/23 detected before the age of 1 year, and 11/33 before 1 month of age. Cardiac manifestations were present in 19 patients: cardiac rhythm disturbances were detected in 13; in 6/33 a Wolff-Parkinson-White syndrome was documented, of which 4 presented paroxysmal arrhythmias. Obstructive or regurgitative phenomena were present in 5; and in 2 patients surgical removal proved necessary. With the exception of one tumoural mass in the right atrium, all 77 tumours were located somewhere in the ventricles, including at atrio-ventricular valve level. Because of spontaneous regression of most of the tumoural masses, treatment should at first be symptomatic, while surgical removal is required only in life-threatening conditions, as documented in 2 of our 33 patients.

A cross sectional study of renal involvement in tuberous sclerosis

Renal disease is a frequent manifestation of tuberous sclerosis (TSC) and yet little is known about its true prevalence or natural history. We reviewed the notes of 139 people with TSC, who had presented without renal symptoms, but who had been investigated by renal ultrasound. Information on the frequency, type, and symptomatology of renal involvement was retrieved. The prevalence of renal involvement was 61%. Angiomyolipomas were detected in 49%, renal cysts in 32%, and renal carcinoma in 2.2%. The prevalence of angiomyolipoma was positively correlated with age, compatible with a two hit aetiology. Renal cysts were the commoner lesion in young children, and their prevalence did not appear to be age related. Renal investigation in people with TSC had been inconsistent and limited. We suggest guidelines for renal investigation in those with TSC.

Morbidity associated with tuberous sclerosis: a population study

Neurological complications and other causes of morbidity were studied in 122 of 131 individuals (64 males, 67 females) with tuberous sclerosis, in a popululation in which its prevalence was 1/26,500. Seizures occurred in 78 per cent, beginning at less that one year of age in 69 per cent (in more males than females in both cases) and after age 16 in 4 per cent. More males than females also had infantile spasms and persistent seizures. Learning disorder occured in 53 per cent (also in more males), all with a history of seizures, and was strongly correlated with age at onset of seizures, type of seizure and outcome for seizure control. Of subjects with learning disorder, 85 per cent required supervision for daily living and 65 per cent had little or no language; 97 per cent were fully mobile. Hemiparesis had occurred in eight of the 131, giant cell astrocytomas in nine bilateral polycystic kidney disease in two, and haemorrhagic complication relating to renal angiomyolipomas in six.

Ruptured hepatic angiolipoma in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) may be associated with hepatic angiomyolipoma. In contradistinction to renal angiomyolipoma this lesion is rare, and nontraumatic hemorrhage has not so far been described. This is the first report of a spontaneously ruptured, surgically treated and histologically verified, hepatic angiomyolipoma in TSC. Anomalies of the vessel walls and consequently the hazard of bleeding are known to increase with the diameter of the tumor in other localizations. It is concluded that in cases with rapid tumor growth and marked vessel anomalies elective surgery should be considered.

Surgical treatment of intraventricular tumors associated with tuberous sclerosis

Six children with intraventricular tumors associated with tuberous sclerosis (TS) were treated at the Children's Health Center, Department of Pediatric Neurosurgery, in the period 1987-1992. The age of the patients ranged from 7 to 15 years. TS was diagnosed according to Gomez diagnostic criteria. Computer tomography (CT) and magnetic resonance imaging showed intraventricular tumors associated with ventricular enlargement and multiple subependymal nodules commonly observed in cases of TS. All tumors were removed totally through frontal transcortical approach, with uneventful postoperative recovery. One patient, with two parallel tumors in the two frontal horns, underwent one-stage surgery with successful total removal. Histopathological examination in all cases showed subependymal giant cell astrocytoma (SGCA). The growth pattern of SGCA associated with TS, documented by sequential CT scans over several years, is described. The diagnosis and surgical treatment of the tumor are discussed, and periodic CT scanning, at least every 2 years, is recommended for patients with TS.

Pulmonary tuberous sclerosis

We describe the clinical presentation, pulmonary function tests, chest radiograph, and computed tomography findings, response to hormonal treatment, and duration of survival of nine patients with pulmonary involvement in tuberous sclerosis complex with follow-up over an average of 17 years (range, 1 to 35 years) since diagnosis. All patients were female, and the average age at onset of symptoms was 16 years (range, 3 months to 39 years); pulmonary symptoms did not develop until an average age of 33 years (range, 22 to 46 years). There was an average delay of 8 years before the correct diagnosis was made. The most common presenting clinical features were seizures, pneumothorax, bleeding into a renal angiomyolipoma, dyspnea, and typical skin changes. Pulmonary function tests commonly demonstrated obstruction to airflow and reduced single-breath diffusing capacity. Chest radiograph and computed tomography characteristically demonstrated diffuse interstitial infiltrates with cystic changes. Two asymptomatic patients with mild pulmonary involvement have remained in stable condition without hormonal therapy. The remaining seven patients had moderate to severe airflow obstruction; of these, five underwent hormonal therapy. Three patients had a clinical response to treatment. Two patients who did not receive hormonal treatment died of progressive respiratory failure. Most patients with pulmonary involvement in tuberous sclerosis have a slowly declining clinical course. Although the available data are limited, they suggest that a trial of hormonal therapy is recommended both for symptomatic patients and for those with declining pulmonary function. Tuberous sclerosis complex should be suspected in all patients with the diagnosis of lymphangioleiomyomatosis.

Deletion of the TSC2 and PKD1 genes associated with severe infantile polycystic kidney disease--a contiguous gene syndrome

Major genes which cause tuberous sclerosis (TSC) and autosomal dominant polycystic kidney disease (ADPKD), known as TSC2 and PKD1 respectively, lie immediately adjacent to each other on chromosome 16p. Renal cysts are often found in TSC, but a specific renal phenotype, distinguished by the severity and infantile presentation of the cystic changes, is seen in a small proportion of cases. We have identified large deletions disrupting TSC2 and PKD1 in each of six such cases studied. Analysis of the deletions indicates that they inactivate PKD1, in contrast to the mutations reported in ADPKD patients, where in each case abnormal transcripts have been detected.

A population study of renal disease in patients with tuberous sclerosis

OBJECTIVE

To establish the prevalence of renal disease, asymptomatic renal lesions and possible renal symptoms in a geographically defined population of individuals with tuberous sclerosis.

PATIENTS AND METHODS

The study involved 131 patients (64 men, 67 women) with tuberous sclerosis who were resident in nine of the districts within the Wessex Region and three Bristol Health Districts and who had been identified by a prevalence study [1]. The patients' mean age was 22 years (range 6 months-74 years). Established renal disease was identified by history. Where possible individuals were seen and were examined. Specific enquiry was made for flank pain and macroscopic haematuria. Renal ultrasound, blood pressure measurement and urine analysis was offered to all individuals with tuberous sclerosis who were resident in the Bath Health District.

RESULTS

Eight patients (6%) had a history of either renal polycystic kidney disease (two patients) or haemorrhage from renal angiomyolipomas (five female patients, one male patient). A further 21% of female and 3% of male patients had a history of severe flank pain or haematuria. Renal ultrasound screening revealed abnormalities in 10 of 21 individuals; angiomyolipomas > 1 cm were found in seven and were twice as common in female patients.

CONCLUSIONS

Regular clinical review of individuals with tuberous sclerosis should include enquiry for renal symptoms and abdominal examination. Lesions > 4 cm are most likely to be symptomatic but longitudinal studies are needed before renal ultrasound screening of adolescents or adults can be recommended.

Genetics of primary brain tumors: a review

In this review we provide evidence for the existence of genes associated with primary malignant brain tumors. We summarize the current knowledge from studies of familial cancer aggregation, hereditary syndromes, and molecular and cytogenetic studies. The epidemiologic evidence is suggestive but inconclusive for an association between brain tumors and cancers in other family members, including cancers of the breast, lung and colon. Central nervous system (CNS) tumors have been associated with several hereditary syndromes including the Li-Fraumeni cancer family syndrome, neurofibromatosis (types 1 and 2), tuberous sclerosis, nevoid basal cell carcinoma syndrome, familial polyposis, and von Hippel-Lindau disease. Significant studies leading to the recognition of molecular and cytogenetic abnormalities in malignant gliomas are described in detail. The genetic studies conducted thus far suggest a role for inherited susceptibility in some CNS tumors.

Renal cystic disease in the tuberous sclerosis complex

Renal cysts are relatively common in tuberous sclerosis, occasionally causing severe cystic disease with renal failure. Although the imaging features and gross appearances resemble dominant polycystic kidney disease, the histopathological appearances are distinctive, perhaps unique, differing from appearances in other forms of renal cystic disease. The cysts are lined with hypertrophic and hyperplastic cells that probably cause the cysts by obstructing lumina. The renal abnormality may be inherent in tuberous sclerosis, although inconstantly expressed. Renal enlargement is sometimes the first recognized expression of tuberous sclerosis, and the occurrence of renal cysts in a child with seizures and developmental retardation leads to a strong suspicion of the diagnosis.

Incidence of hepatic hamartomas in tuberous sclerosis

Hepatic hamartomas were thought to be a rare finding in patients with tuberous sclerosis. The purpose of this study was to assess their incidence in children with tuberous sclerosis and to review the literature. During 1984-90 we examined 51 children by ultrasonography; there were 25 boys and 26 girls. Their age ranged from 3 months to 18 years. Liver hamartomas were seen in 12 (23.5%) of the children, more often in girls than boys (5:1). Their incidence increased with age reaching 45% in children over the age of 10. They did not produce any symptoms of hepatic dysfunction. Our study and review of reported cases prove that hepatic hamartomas are a common finding in patients with tuberous sclerosis and may be very helpful in providing a more accurate diagnosis and consequently help in genetic counselling.

Linkage of an important gene locus for tuberous sclerosis to a chromosome 16 marker for polycystic kidney disease

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder of unknown aetiology that affects numerous body systems including skin, brain and kidneys. Some TSC has been linked to chromosome 9, additional TSC genes on chromosomes 11 and 12 have been proposed, but the majority of TSC families remain unlinked. Using TSC families in which data had excluded linkage to chromosome 9, we failed to detect linkage with loci on chromosomes 11, 12 and others. One marker examined was D16S283, the closest locus on the proximal side of the polycystic kidney disease type 1 (PKD1) gene. Linkage between TSC and D16S283 demonstrated a lod score of 9.50 at theta = 0.02 with one family independently presenting a lod score of 4.44 at theta = 0.05. These data reveal an important TSC locus near the region of PKD1 on chromosome 16p13.