Peutz-Jeghers Syndrome

A number sign (#) is used with this entry because Peutz-Jeghers syndrome (PJS) is caused by heterozygous mutation in the serine/threonine kinase STK11 gene (602216) on chromosome 19p13.

Description

Peutz-Jeghers syndrome is an autosomal dominant disorder characterized by melanocytic macules of the lips, buccal mucosa, and digits; multiple gastrointestinal hamartomatous polyps; and an increased risk of various neoplasms.

Clinical Features

In the syndrome named for Peutz (1921) and Jeghers (Jeghers et al., 1949), polyps may occur in any part of the gastrointestinal tract but jejunal polyps are a consistent feature. Intussusception and bleeding are the usual symptoms. Melanin spots of the lips, buccal mucosa, and digits represent the second part of the syndrome. Malignant degeneration of the small intestinal polyps is rare. Metastases from a malignant polyp in Peutz-Jeghers syndrome was reported by Williams and Knudsen (1965). Dodds et al. (1972) found 15 cases of gastrointestinal carcinoma in Peutz-Jeghers syndrome: 5 in colon, 4 in duodenum, 4 in stomach, 1 in ileum, and 1 in both jejunum and stomach. In the family reported by Farmer et al. (1963), the father had only polyps, the son apparently only pigmentation, and the daughter both polyps and pigmentation. Kieselstein et al. (1969), who found polycystic kidney disease in the same family, also noted a dissociation of signs. Brigg et al. (1976) observed a case of presumed Peutz-Jeghers syndrome without spots or positive family history. Hamartomatous polyps were limited to the jejunum and caused bleeding. Griffith and Bisset (1980) reported 3 cases. In 2 of them, the family history was negative; in the third, the father and a paternal uncle had melanin spots of the lips but no history of intestinal disorder.

Sommerhaug and Mason (1970) added the ureter to the sites of polyps described in the Peutz-Jeghers syndrome. Previously described extraintestinal sites include esophagus, bladder, renal pelvis, bronchus and nose. Burdick and Prior (1982) reported nonresectable adenocarcinoma of the jejunum arising in a Peutz-Jeghers polyp and accompanied by metastases in mesenteric lymph nodes. Two developed breast carcinoma of which 1 arose in a fibroadenoma. Three had benign ovarian tumors, 1 had a benign breast tumor and 1 had a benign colloid thyroid nodule. One of the cases (case 7) reported by Jeghers et al. (1949) died of pancreatic cancer. Bowlby (1986) reported pancreatic cancer in an adolescent boy with PJS.

Affected females are prone to develop ovarian tumor, especially granulosa cell tumor (Christian et al., 1964). Wilson et al. (1986) described gynecomastia and multifocal and bilateral testicular tumors in a 6-year-old boy with PJS. The testicular tumors appear to be of Sertoli cell origin and most are calcifying. Two previously reported cases were found. Coen et al. (1991) reported the case of a 4-year-old boy with Peutz-Jeghers syndrome and bilateral sex-cord testicular tumors resulting in gynecomastia. Studies led to the conclusion that increase in aromatase activity (107910) in the gonadal tumors was responsible for estrogen excess and gynecomastia. Three other reported male patients with Peutz-Jeghers syndrome and gonadal tumors had presented with gynecomastia between birth and 6 years of age. They pointed out that multifocal sex-cord tumors were found in palpably normal testes. The occurrence of ovarian tumors far exceeds that of testicular tumors in this disorder. The production of estrogen by ovarian tumors is indicated by the reported appearance of isosexual precocity in girls with PJS (Solh et al., 1983). Young et al. (1995) reported 2 boys, aged 3.5 and 5.5 years, who were evaluated for gynecomastia and found to have multicentric Sertoli cell testicular tumors responsible for their feminization. Both had rapid growth and advanced bone age, and serum levels of estradiol were markedly elevated.

Bergada et al. (2000) described a 7-year-old boy with Peutz-Jeghers syndrome, gynecomastia, and bilateral neoplastic Sertoli cell proliferation in whom the only abnormal hormonal profile was increased concentration of inhibin-beta (see 147290), which was biologically active, and pro-alpha C of insulin, which was biologically inactive.

In a patient with both psoriasis and Peutz-Jeghers syndrome (sine polyps), Banse-Kupin and Douglass (1986) described a peculiar phenomenon: the development of characteristic pigmented macules within preexisting psoriatic plaques in sites highly unusual for PJS, e.g., on the elbow, back of the neck and occipital scalp, buttocks, and legs. Sommerhaug and Mason (1970) suggested that patients with PJS develop polyps in areas of frequent trauma. Banse-Kupin and Douglass (1986) proposed that pigmented macules may likewise be located in areas of frequent trauma or areas of inflammation. Inflammation may induce blockage of pigment transfer from melanocyte to keratinocyte, resulting in a macule. As the inflammation or trauma subsides, so may the blockage and the lesion may fade. Histologically, the oral mucosal lesions resemble lentigo simplex, but the acral lesions are distinctive (Yamada et al., 1981). There is an increased number of melanocytes with long dendrites filled with melanosomes but few melanosomes in keratocytes, suggesting a pigment block.

Giardiello et al. (1987) investigated the occurrence of cancer in 31 patients with PJS followed from 1973 to 1985. Gastrointestinal carcinoma developed in 4, nongastrointestinal carcinoma in 10, and multiple myeloma in 1. Adenomatous polyps of the stomach and colon occurred in 3 other patients. There were 4 cases of pancreatic cancer. Foley et al. (1988) provided a 49-year follow-up of the 'Harrisburg family,' 3 affected members of which were reported by Jeghers et al. (1949). The family had also been studied earlier by Bartholomew et al. (1962). In all, 12 affected members have been identified, making this the largest PJS kindred reported. One member of the family had developed a duodenal carcinoma and a hamartoma with adenomatous changes. Another member developed short bowel syndrome. In the follow-up of 72 patients with PJS in the St. Mark's Polyposis Registry, Spigelman et al. (1989) found that malignant tumors had developed in 16 (22%), of whom all but 1 had died. There were 9 gastrointestinal and 7 nongastrointestinal tumors. The chance of dying of cancer by age 57 was 48%.

Westerman and Wilson (1999) reviewed the literature on PJS, with particular emphasis on the risks for PJS gene carriers. The risks imposed by polyps included surgical emergencies like small bowel intussusception, and chronic or acute bleeding from the polyps. Many reports, however, suggested an association of PJS with both gastrointestinal and nongastrointestinal malignancies, often at a young age. The frequent occurrence of rare tumors of the ovary, cervix, and testis indicated a general susceptibility for the development of malignancies. The PJS gene was therefore thought to act as a tumor suppressor gene. The authors suggested that a surveillance protocol should be developed for the prevention of cancer in PJS.

Unusually early age of onset was observed by Fernandez Seara et al. (1995) in a 15-day-old girl who was found to have generalized gastrointestinal polyposis manifested by abdominal distention, hematemesis, bloody diarrhea, and edema. At 15 days of age, ileocecal intussusception causing intestinal obstruction was diagnosed radiologically and reduced by hydrostatic enema; ileocecal surgical resection was required, however. Rectal prolapse due to a large polyp occurred at one month of age. Esophagogastroscopy showed polyps in the stomach; one in the antrum partially obstructed the lumen. No hyperpigmentation of the lips or oral mucosa was observed at any time and none was present in her relatives. The histologic appearance of the polyps removed during life and at autopsy was consistent with Peutz-Jeghers syndrome.

Gruber et al. (1998) noted that the histopathologic appearance of hamartomas in PJS is distinct from that of other types of gastrointestinal polyps and likely reflects a different pathogenetic sequence for their development. PJS hamartomas show an elongated, frond-like epithelium with cystic dilatation of glands overlying an arborizing network of smooth muscle bundles. Hypermucinous goblet cells are often prominent. In addition, pseudoinvasion by histopathologically benign epithelium is common in PJS hamartomas. These characteristic features are easily distinguished from the cytologic atypia and lack of differentiation seen in typical adenomas, and it is not surprising that PJS tumors seem to share few of the earliest genetic events observed in the transition of normal epithelium to dysplastic adenomas. Hamartomatous polyps arising in the juvenile polyposis syndrome (174900) originate through yet another mechanism as a consequence of germline mutations in the SMAD4/DPC4 gene (600993). The hamartomas of juvenile polyposis are histologically distinct from those of PJS, and the risk of malignancy also differs in these 2 syndromes.

Some patients with PJS may be disturbed by the appearance of lentigines. Kato et al. (1998) described ruby laser therapy of labial lentigines in 2 children with this disorder. They stated that the response to treatment was excellent, with no sequelae or recurrence of the lesions.

Boardman et al. (2000) pointed out that diagnosing PJS, even in an individual from a known PJS kindred, can be difficult. Oral pigmentation tends to fade and be forgotten with time, and polyps can often be asymptomatic. Additionally, other syndromes may mimic the pigmentation of PJS, occurring in individuals with an occult malignancy (Babin et al., 1978; Eng et al., 1991; Gass and Glatzer, 1991) or in individuals with Laugier-Hunziker syndrome, a condition characterized by oral hyperpigmentation without polyposis (Veraldi et al., 1991).

Familial hamartomatous polyps of the small intestine resembling those of PJS were recognized as a feature of Bannayan-Zonana syndrome (BRRS; see 158350), which is caused by mutation in the PTEN gene (601728), by DiLiberti et al. (1983) and others. Pigmented spots occur also in BRRS but characteristically on the glans penis in males and not on the lips.

In connection with the possibility that the melanin spots of the lips represent a benign neoplasm, the observations of Jeghers et al. (1949) may be significant: clinically, some of the spots could be seen to have a somewhat stippled appearance under magnification, which, it was thought, could be explained by a curious histologic pattern observed on biopsy. The pigmentation occurred mainly in vertical bands interrupted by unpigmented areas. The change suggested the possibility of clonality.

Mapping

Studying 2 extended families, Bali et al. (1995) found positive evidence for linkage with several microsatellite markers on chromosome 1. Seldin (1997) reported that addition of more family members in the 2 largest families decreased the lod scores substantially as did the addition of more markers in the region. Indeed, in the original study, the maximum 2-point lod was below 2.0. Multipoint linkage analysis yielded a maximum lod score of 4.00 at D1S220. This is located in the distal region of 1p, where the human homolog of the putative modifier of multiple intestinal neoplasias (172411) had previously been mapped.

In a patient with Peutz-Jeghers syndrome, Markie et al. (1996) demonstrated a pericentric inversion in chromosome 6. Using fluorescence in situ hybridization with YAC clones selected to contain genetic markers from chromosome 6 and with a probe for the centromeric alphoid array, they located 1 inversion breakpoint within the alphoid repeat array, in a 1-cM interval between D6S257 and D6S402, and the other in a 4-cM interval between D6S403 and D6S311.

To localize the susceptibility locus for Peutz-Jeghers syndrome, Hemminki et al. (1997) used comparative genomic hybridization (CGH) and targeted linkage analysis, combined with loss of heterozygosity (LOH) study. They demonstrated a high-penetrance locus in distal 19p with a multipoint lod score of 7.00 at marker D19S886 without evidence of genetic heterogeneity. The study demonstrated the power of CGH combined with LOH analysis in identifying putative tumor suppressor loci. In comparative genomic hybridization, a single hybridization allows DNA copy number changes in the whole genome of a tumor to be assessed in comparison with normal tissue DNA (Kallioniemi et al., 1992). The findings of Hemminki et al. (1997) suggested that in most or all of the families they studied, the PJS was caused by a defect in a single locus on 19p. That the Peutz-Jeghers syndrome is genetically homogeneous required, however, confirmation by linkage analysis in further families. Amos et al. (1997) confirmed the mapping of PJS to the telomeric region of 19p. In the 5 families examined, there were no recombinants with the marker D19S886. The multipoint lod score at D19S886 was 7.52, and they found no evidence for genetic heterogeneity or of reduced penetrance.

Mehenni et al. (1997) performed a genomewide linkage analysis, using DNA polymorphisms in 6 families (2 from Spain, 2 from India, 1 from the U.S., and 1 from Portugal), including 39 affected individuals and 6 individuals of unknown status. Marker D19S886 yielded a maximum lod score of 4.74 at a recombination fraction of 0.45; multipoint linkage analysis resulted in a lod score of 7.51 for the interval between D19S886 and 19pter. However, markers on 19q13.4 also showed significant evidence for linkage. For example, D19S880 resulted in a maximum lod score of 3.8 at theta = 0.13. Most of this positive linkage was contributed by a single family. Thus, the results confirmed the mapping of a common PJS locus on 19p13.3, but also suggested the existence, in a minority of families, of a potential PJS locus on 19q13.4. Buchet-Poyau et al. (2002) excluded several candidate genes as a second PJS locus in the 19q13.3-q13.4 region.

Molecular Genetics

Within a distance of 190 kb proximal to D19S886, the marker with the highest lod score in the study of Hemminki et al. (1997), Jenne et al. (1998) identified and characterized a novel human gene encoding the serine/threonine kinase STK11. In a 3-generation PJS family, they found an STK11 allele with a deletion of exons 4 and 5 and an inversion of exons 6 and 7 (602216.0001) segregating with the disease. Sequence analysis of STK11 exons in 4 unrelated PJS patients identified 3 nonsense mutations (602216.0002, 602216.0003, 602216.0004) and 1 acceptor splice site mutation (602216.0005). All 5 germline mutations were predicted to disrupt the function of the kinase domain. Jenne et al. (1998) concluded that germline mutations in STK11, probably in conjunction with acquired genetic defects of the second allele in somatic cells, caused the manifestations of PJS.

Independently and simultaneously, Hemminki et al. (1998), the group that identified the linkage of PJS to chromosome 19, demonstrated mutations in the serine/threonine kinase gene in 11 of 12 unrelated patients with PJS.

Jenne (1998) speculated that cellular context between melanocytes and keratinocytes are regulated by STK11 activity. He pointed to the wide tissue distribution of STK11 and suggested that effects in melanocytes may be observed preferentially at sites of mechanical and physical stress.

Gruber et al. (1998) studied 6 families with PJS from the Johns Hopkins Polyposis Registry to identify the molecular basis of PJS and to characterize the pathogenesis of gastrointestinal hamartomas and adenocarcinomas in these patients. Linkage analysis in the family studied by McKusick, who contributed to the publication of Jeghers et al. (1949), and in 5 other families confirmed linkage to 19p13.3. Germline mutations in STK11 were identified in all 6 families by sequencing genomic DNA. Analysis of hamartomas and adenocarcinomas from patients with PJS identified LOH of 19p markers near STK11 in 70% of tumors. Haplotype analysis indicated that the retained allele carried a germline mutation (602216.0012), confirming that STK11 is a tumor suppressor gene. LOH of 17p and 18q was identified in an adenocarcinoma but not in hamartomas, implying that allelic loss of these 2 regions corresponds to late molecular events in the pathogenesis of cancer in PJS. The adenocarcinomas showing 17p LOH also demonstrated altered p53 by immunohistochemistry. None of the 18 PJS tumors showed microsatellite instability, LOH on 5q near APC (611731), or mutations in codons 12 or 13 of the KRAS2 (190070) protooncogene. These data provided evidence that STK11 is a tumor suppressor gene that acts as an early gatekeeper regulating the development of hamartomas in PJS and suggested that hamartomas may be pathogenetic precursors of adenocarcinoma. Additional somatic mutation events underlie the progression of hamartomas to adenocarcinomas, and some of these somatic mutations are common to the later stages of tumor progression seen in the majority of colorectal carcinomas.

Miyaki et al. (2000) presented findings suggesting that gastrointestinal hamartomatous polyps in PJS patients develop through inactivation of the STK11 gene by germline mutation plus somatic mutation or LOH of the unaffected STK11 allele, and that additional mutations of the beta-catenin gene (CTNNB1; 116806) and the p53 gene (TP53; 191170) convert hamartomatous polyps into adenomatous and carcinomatous lesions.

Westerman et al. (1999) found novel STK11 mutations in 12 of 19 predominantly Dutch families with PJS. No mutation was found in the remaining 7 families. None of the mutations occurred in more than 1 family, and a number were demonstrated to have arisen de novo. The likelihood of locus heterogeneity was raised.

Jiang et al. (1999) conducted a detailed investigation of germline STK11 alterations by protein truncation test and genomic DNA sequence analysis in 10 unrelated PJS families. A novel truncating deletion in a single patient and several known polymorphisms were identified. The results suggested that STK11 mutations account for only some cases of PJS.

Boardman et al. (2000) searched for mutations in the STK11 gene in 5 kindreds with more than 2 family members affected by PJS, 5 PJS probands with only 1 other affected family member, and 23 individuals with sporadic PJS. Conformation-sensitive gel electrophoresis was used for the initial screen, followed by direct sequence analysis for characterization. Long-range PCR was used for the detection of larger genetic insertions or deletions. Genetic alterations in the gene were found in 2 probands who had a family history of PJS. Mutations were detected in the gene in only 4 of the 23 patients with sporadic PJS. The authors interpreted these data as suggesting the presence of significant genetic heterogeneity in PJS and the involvement of other loci in this syndrome. They pointed to the report by Mehenni et al. (1997) of a possible second susceptibility locus on 19q in 2 PJS Indian families and to that by Olschwang et al. (1998), in which no evidence of linkage was found in 3 of 20 PJS kindreds.

Olschwang et al. (2001) studied 34 families with PJS. Mutations in the STK11 gene were identified in 24 families. In the 10 families in which mutations were not identified, there was a significantly increased risk of proximal biliary adenocarcinoma.

Westerman et al. (1999) traced the Dutch family reported by Peutz (1921) and determined that the affected members carried a previously unidentified germline mutation in the STK11 gene (602216.0014). The pedigree, published by Westerman et al. (1999), showed affected individuals in 4 generations and, by inference, in an earlier fifth generation. In total, 22 persons (9 females and 13 males) were affected and 31 were unaffected. Nasal polyposis was present in 2 members of 1 generation and in 4 members of another. Colicky abdominal pain occurred in all 22 affected members, paralytic ileus in 16, chronic anemia in 9, and acute or chronic blood loss in 14. Rectal prolapse due to polyps occurred in 7. In 4 patients, the nasal polyposis was severe, obstructing the nasal cavity and sinuses, requiring repeated surgery. In 1 woman who had had extremely severe nasal polyposis since childhood, a squamous cell carcinoma of the nasal cavity developed. She died of this tumor 4 years later. Three of the 5 cases of gastrointestinal cancer were in the colon, 1 was in the stomach, and 1 was of unknown primary origin. Breast cancer occurred in a female patient at the age of 47 years. Premenopausal breast cancer was diagnosed in a sib at the age of 44; it was not known whether this patient was affected by PJS. No other cancers of the reproductive tract were found in this family.

Keller et al. (2002) reported molecular genetic evidence of an association between nasal polyposis and PJS. They studied 12 nasal polyps from 4 patients with PJS who came from 3 families with known germline mutations in STK11, and 28 sporadic nasal polyps from 28 subjects without evidence of PJS, Kartagener syndrome (244400), cystic fibrosis (CF; 219700), or aspirin sensitivity. In 2 unrelated patients with PJS, 4 of 8 nasal polyps showed loss of heterozygosity at 19p13.3. In contrast, loss of heterozygosity was not found in 23 sporadic nasal polyps. Haplotype analysis showed that loss of heterozygosity comprised deletion of the wildtype allele. Loss of heterozygosity at 19p13.3 in nasal polyps of affected patients corresponded with reports of loss of heterozygosity in gastrointestinal hamartomatous polyps (Entius et al., 2001). In his original publication, Peutz (1921) suggested that nasal polyps represent an extraintestinal manifestation of PJS.

Le Meur et al. (2004) reported a family with typical features of PJS, including melanin spots of the oral mucosa, gastrointestinal hamartomatous polyps, and breast and colon cancer. The authors noted that the proband had neurofibromatosis type I (162200) of paternal origin as well as PJS of maternal origin. Using quantitative multiplex PCR of short fluorescent fragments of the 19p13 region, they identified an approximately 250-kb heterozygous deletion that completely removed the STK11 locus. Le Meur et al. (2004) stated that this was the first report of a complete germline deletion of STK11 and suggested that the presence of such large genomic deletions should be considered in PJS families without detectable point mutations of STK11.

Amos et al. (2004) screened 42 independent probands for mutations in the STK11 gene and detected mutations in 22 of 32 (69%) probands with PJS and 0 of 10 probands referred to rule out PJS. In a total of 51 participants with PJS, the authors found gastric polyps to be very common, with a median age at onset of 16 years. Individuals with missense mutations had a significantly later time to onset of first polypectomy (p = 0.04) and of other symptoms compared with those participants with either truncating mutations or no detectable mutation. Amos et al. (2004) concluded that STK11 mutation analysis should be restricted to individuals who meet PJS criteria or their close relatives, and suggested that mutation characterization might be of value in disease management. They also noted that the common occurrence of gastric polyps might facilitate chemopreventive studies for this disorder.

In a 20-year-old female patient with PJS and gastrointestinal hamartomatous polyps, Hernan et al. (2004) identified a de novo heterozygous germline tyr246-to-ter mutation of the STK11 gene (602216.0023). Comparison of melting curve profiles obtained from DNA from the patient's lymphocytes and hamartomatous polyps showed no differences, indicative of a heterozygous mutation rather than loss of heterozygosity in the polyps. Hernan et al. (2004) suggested that biallelic inactivation of STK11 is not necessarily required for hamartoma formation in PJS patients.

In a patient with PJS and a primary gastric cancer (137215), Shinmura et al. (2005) identified heterozygosity for a deletion mutation of the STK11 gene (602216.0022), resulting in a truncated protein. No inactivation of the wildtype allele by somatic mutation, chromosomal deletion, or hypermethylation at the 5-prime CpG site of STK11 was detected in the gastric carcinoma. The patient's sister also had PJS and died of gastric carcinoma in her twenties. Shinmura et al. (2005) stated that this was the first report of an STK11 germline mutation in a PJS patient with gastric carcinoma.

Genetic Heterogeneity

Alhopuro et al. (2008) identified a heterozygous germline mutation in the MYH11 gene (160745) in 1 of 33 PJS patients who did not have STK11 mutations, and the mutation was not identified in 1,015 controls. The patient had a cystic astrocytoma at age 13 years. At age 23 years, he developed intussusception and was diagnosed with typical PJS. His unaffected father also carried the mutation; there was no family history of the disorder. The authors postulated autosomal recessive inheritance and the presence of a second unidentified MYH11 mutation. In an unrelated patient with colorectal tumor showing microsatellite instability, Alhopuro et al. (2008) identified the same mutation in the somatic state.

Genotype/Phenotype Correlations

In a study of 132 PJS patients with or without cancer who had mutations in the STK11 gene, Schumacher et al. (2005) found that mutations in the part of the gene involved in ATP binding and catalysis were rarely associated with cancer, whereas mutations in the part of the gene involved in substrate recognition were more frequently associated with malignancies. PJS patients with breast cancers had predominantly truncating mutations.

History

Although Peutz (1921) was the first to recognize the familial association of gastrointestinal polyposis and mucocutaneous pigmentation, cases of gastrointestinal and, in particular, polyposis of the small intestine had been described before him. Many of these may have been instances of Peutz-Jeghers syndrome in which the characteristic pigmentation was not noticed or its significance was not appreciated. Two extensive reviews put the polyps-and-spots syndrome 'on the map': the review by Jeghers et al. (1949) in 2 successive weekly issues of the New England Journal of Medicine, and, describing 10 personal cases, the review by Dormandy (1957) in 3 successive weekly issues of the same journal. The designation Peutz-Jeghers syndrome appears to have first been used (at least in the title of an article) by Bruwer et al. (1954) of the Mayo Clinic. If in several early reports of small intestinal polyposis the characteristic pigmentation of PJS may have passed unnoticed, the reverse is certainly true. Jeghers et al. (1949) called attention to the first account of such cases, in female twins, by Hutchinson (1896). Hutchinson (1896) stated that the pigmented spots 'remain nonaggressive and their subjects remain in good health.' Weber (1919) reported that 'one of the twins had died at the age of 20 years of intussusception at the Metropolitan Hospital.' Jeghers et al. (1949) obtained follow-up information on Hutchinson's twins of the family name Howard. They were daughters of the official rat catcher of city of London. The second twin died childless of breast cancer at the age of 52 years. The breast cancer was considered coincidental at the time of the follow-up, but the findings of Giardiello et al. (1987) and the demonstration that the gene that is mutant in PJS is a tumor suppressor gene, make the cause of death in the second twin highly significant.

Keller et al. (2002) provided a history of the Peutz-Jeghers syndrome, with biographic information concerning both Jan Peutz and Harold Jeghers.