The PTEN hamartoma tumor syndrome, manifestations of which include Cowden disease and Bannayan-Riley-Ruvalcaba syndrome, is caused by various mutations of the PTEN gene located at 10q23. Its major criteria are macrocephaly and a propensity to develop breast and thyroid cancers as well as endometrial carcinoma. Minor diagnostic criteria include hamartomatous intestinal polyps, lipomas, fibrocystic disease of the breasts, and fibromas. Mutations of PTEN can also be found in patients with Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum). The authors report the case of a 17-year-old girl who had a severe cyanotic cardiac malformation for which surgery was not advised and a heterozygous missense mutation (c.406T>C) in exon 5 of PTEN resulting in the substitution of cysteine for arginine (p.Cysl36Arg) in the protein, which was also found in her mother and sister. The patient presented in the pediatric emergency department with severe spastic paraparesis. A magnetic resonance imaging study of the spine showed vertebral hemangiomas at multiple levels, but stenosis and compression were maximal at level T5-6. An emergency T5-6 laminectomy was performed. The decompression was extremely hemorrhagic because the rapid onset of paraparesis necessitated prompt treatment, and there was no time to perform preoperative embolization. The patient's postoperative course was uneventful with gradual recovery. This represents the first report of an association of a PTEN mutation and multiple vertebral angiomas. The authors did not treat the remaining angiomas because surgical treatment was contraindicated without previous embolization, which in itself would present considerable risk in this patient with congenital cyanotic heart disease.
"T- > C, p.136Cys- > Arg in exon 5 of PTEN gene (Figure 1A). This mutation, already described in the literature, results in amino acid substitution of cysteine into an arginine residue at position 136 [7,8]. "
[Show abstract][Hide abstract] ABSTRACT: Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS) and proteus syndrome are disorders known as PTEN hamartoma tumour syndrome (PHTS), that can show remarkable clinical overlap and are all caused by germline PTEN mutations.
We here present two families, one affected by CS and the other affected by BRRS, both carriers of specific pathogenetic missense mutation in exon 5 of PTEN gene, within the catalitic domain. Both PHTS families exhibited extremely variable phenotypes, showing inter- and intra- familial variability. One of the two characterised mutations, the c.320A- > T; p.107Asp- > Val, identified in the CS family, was not previously described in the literature. Furthermore, the BRRS family, carrier of the c.406 T- > C; p.136Cys- > Arg mutation, shows a substantial alteration of PTEN protein expression that well correlates with intra-familial phenotypic variability.
Finally, we describe an apparently sporadic case of an 80-year-old man, with a very low level of PTEN mRNA and protein expression, both in healthy and tumour colon mucosa, associated with a very atypical phenotype. He developed a metastatic colorectal carcinoma, macrocephaly and pheochromocytoma.
According to literature data, our observations confirm that PTEN mutations of catalytic domain can cause different syndromes. We suggest that PTEN expression could represent one of the mechanisms involved in the remarkable heterogeneity of the clinical PHTS manifestations within affected families. Furthermore, constitutive strong decrease of PTEN expression in colon normal mucosa could be associated with late onset of colorectal cancer.
Hereditary Cancer in Clinical Practice 07/2013; 11(1):8. DOI:10.1186/1897-4287-11-8 · 1.47 Impact Factor
"They concluded in this research that macrocephalic patients with fast-flow vascular anomalies or multiple intracranial developmental venous anomalies should be tested for PTEN mutation . Although a few cases have been reported with the association of CS, hemangiomas and arteriovenous malformations are reported features of BRRS . Electromyography may reflect the myopathic process . "
[Show abstract][Hide abstract] ABSTRACT: Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare autosomal, dominantly-inherited, hamartoma syndrome with distinct phenotypic features. Mutations in the PTEN gene have been identified in PTEN hamartoma tumor syndromes. Our aim was to determine the correlation of phenotype-genotype relationships in a BRRS case. We have evaluated a PTEN mutation in a patient with vascular anomalies and the phenotypic findings of BRRS. We described an 8-year-old girl with the clinical features of BRRS, specifically with vascular anomalies. The mutation in the PTEN gene was identified by DNA sequencing. In our patient, we defined a de novo nonsense R335X (c.1003 C>T) mutation in exon 8, which results in a premature termination codon. Due to vascular anomalies and hemangioma, the patient's left leg was amputated 1 year after the hemangioma diagnosis. Bannayan - Riley - Ruvalcaba syndrome patients with macrocephaly and vascular anomalies should be considered for PTEN mutation analysis and special medical care.
Balkan Journal of Medical Genetics 06/2012; 15(1):45-50. DOI:10.2478/v10034-012-0007-x · 0.50 Impact Factor
"As shown in Table 1 patient PHTS1, affected by BRRS, had a missense mutation named c.406T→C in exon 5 of PTEN gene. This mutation, already described in the literature, determines the aminoacidic change of a cysteine residue at position 136 into an arginine [13,14]. The other two patients, PHTS2 and PHTS3 (both affected by CS), showed a significant decrease in the PTEN mRNA expression when analysed by Real Time quantitative RT-PCR (Figure 1a) (unpaired two-tailed t test, confident intervals 99% p: 0,0002); this statistic result was the same when calculated with the twenty healty controls separately and with the four mixes of healty subject (data not shown). "
[Show abstract][Hide abstract] ABSTRACT: The "PTEN hamartoma tumor syndrome" (PHTS) includes a group of syndromes caused by germline mutations within the tumor suppressor gene "phosphatase and tensin homolog deleted on chromosome ten" (PTEN), characterized by multiple polyps in the gastrointestinal tract and by a highly increased risk of developing malignant tumours in many tissues. The current work clarifies the molecular basis of PHTS in three unrelated Italian patients, and sheds light on molecular pathway disregulation constitutively associated to PTEN alteration.
We performed a combination of RT-PCR, PCR, sequencing of the amplified fragments, Real Time PCR and western blot techniques.
Our data provide the first evidence of β-catenin accumulation in blood cells of patients with hereditary cancer syndrome caused by germ-line PTEN alteration. In addition, for the first time we show, in all PHTS patients analysed, alterations in the expression of TNFα, its receptors and IL-10. Importantly, the isoform of TNFRI that lacks the DEATH domain (TNFRSF1β) was found to be overexpressed.
In light of our findings, we suggest that the PTEN pathway disregulation could determine, in non-neoplastic cells of PHTS patients, cell survival and pro-inflammatory stimulation, mediated by the expression of molecules such as β-catenin, TNFα and TNFα receptors, which could predispose these patients to the development of multiple cancers.
BMC Medical Genetics 04/2012; 13(1):28. DOI:10.1186/1471-2350-13-28 · 2.08 Impact Factor
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