Alternative titles; symbols
SNOMEDCT: 719475006; ORPHA: 140944; DO: 0080351;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 3q26.32 | CLOVE syndrome, somatic | 612918 | 3 | PIK3CA | 171834 |
A number sign (#) is used with this entry because of evidence that congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE syndrome) can be caused by somatic mosaicism for postzygotic activating mutations in the PIK3CA gene (171834) on chromosome 3q26.
Sapp et al. (2007) described 7 patients with an apparently distinct overgrowth syndrome with only some similarities to Proteus syndrome (176920). All 7 patients had progressive, complex, and mixed primarily truncal vascular malformations, dysregulated adipose tissue, varying degrees of scoliosis, and enlarged, but not severely distorted, bony structures without progressive overgrowth. In contrast to the bony distortion characteristic of Proteus syndrome, bony distortion in these patients occurred only in areas of the body that had undergone major or radical surgery. Two of the patients had previously been reported as having Proteus syndrome, one by Eldredge et al. (1993) and the other by Biesecker et al. (1998) and Jamis-Dow et al. (2004). Sapp et al. (2007) designated the condition congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE syndrome).
Gucev et al. (2008) described a neonate with features of CLOVE syndrome who also had hemimegalencephaly with agenesis of the corpus callosum, ptosis, horizontal nystagmus, and bilateral cataracts. Gucev et al. (2008) suggested that case 2 reported by McCall et al. (1992) had CLOVE syndrome.
Alomari (2009) identified 18 unrelated patients with CLOVES syndrome. The patients had a lipomatous mass that infiltrated the adjacent anatomic spaces and was associated with capillary, lymphatic, venous, and arteriovenous vascular malformations. They also had large, wide feet and hands, macrodactyly, and a wide sandal gap, scoliosis, and other musculoskeletal, neurologic, renal, and cutaneous malformations. They had morbid paraspinal high-flow lesions and phlebectasia. Alomari (2009) suggested that the patients described by Atalar et al. (2006) and Ram and Noor (1993) most likely had CLOVES syndrome.
Lindhurst et al. (2012) described 11 individuals with a previously uncharacterized progressive segmental overgrowth syndrome. The major manifestation was segmental progressive overgrowth of subcutaneous, muscular, and visceral fibroadipose tissue with skeletal overgrowth. Seven of 8 patients had congenital overgrowth. There was a wide range of severity and of natural history among the affected individuals. Patient C1 had massive overgrowth of her body from the waist down, weighing 117 kg, with leg circumferences of 100-110 cm. Her total adiposity, assessed by dual-energy x-ray absorptiometry (DXA), was 50%, accounted for mostly by her legs. Her overgrowth continued into adulthood. In contrast, patient C2 had overgrowth limited to an arm and thumb, and patient N110 had overgrowth limited to 2 rays of 1 foot. Patient N7 had an extensive lipoma of the left lower trunk, buttock, and leg that necessitated amputation. Patient N45 had fibroadipose overgrowth of the lower body, including a pelvic mass that encased the rectum with attendant constipation. The overgrowth in this individual continued into adulthood. However, the overgrowth in patient N68 mostly ceased after puberty. Skeletal overgrowth was variable in character. Four individuals had skeletal overgrowth with preserved architecture, whereas others had distorting overgrowth. Several individuals had enlarged peripheral nerves, cutaneous vascular malformations, and testicular or epididymal cysts and hydroceles. Four individuals had marked lipoatrophy in areas not affected by overgrowth, but no evidence for either insulin resistance or hypoglycemia was reported. None of the affected individuals had reported malignancies, although patient N108 did have benign nephrogenic rests.
Venot et al. (2018) treated 2 patients with severe CLOVES/PIK3CA-related overgrowth, 1 adult and 1 child, with BYL719 (alpelisib), a PIK3CA inhibitor developed to treat cancer. Marked clinical improvement occurred rapidly after the onset of treatment in both patients, with progressive reduction in tumor size, venous dilations, and skin lesions. Congestive heart failure in the adult improved, scoliosis in the child was attenuated, and hemihypertrophy in both was reduced. On the basis of those results, Venot et al. (2018) treated 17 additional patients (14 children and 3 adults) with severe PIK3CA-related overgrowth, all with documented gain-of-function PIK3CA mutations, with BYL719. Of the 17 patients, 6 had been diagnosed with CLOVES, 2 with MCAP, and 9 with localized overgrowth syndrome. Eight patients had received rapamycin treatment for 18 months without clinical or radiologic improvement. After BYL719, all patients showed substantial clinical improvement. All patients had reduced size of lesions and some clinical improvement in scoliosis. After 6 months of treatment, all patients were still alive and no surgery had been performed. All 19 patients received the lowest dose used in clinical trials, 250 mg/day for adults and 50 mg/day for children. Based on results in the mouse model (see ANIMAL MODEL), all 19 patients remained on BYL719 treatment after the end of the follow-up period.
Venot et al. (2018) developed a mouse model of CLOVES by creating mice that express a dominant-active PIK3CA transgene and ubiquitously express PIK3CA upon tamoxifen administration to induce Cre recombination. Three-week-old mice treated with a single dose of tamoxifen (40 mg/kg) began to die rapidly, with 50% mortality at day 9. Death occurred suddenly in most cases, with necropsy revealing intraabdominal and hepatic hemorrhages. Whole-body MRI showed scoliosis, vessel abnormalities, kidney cysts, and muscle hypertrophy. Histologic examination revealed liver steatosis with vessel disorganization, loss of spleen microarchitecture integrity, spontaneous hemorrhages, and fibrosis of the kidney with aberrant vessels. Venot et al. (2018) administered either BYL719 (alpelisib) or placebo to mutant mice orally each day starting on the day of Cre induction. While all placebo-treated mutant mice died within 15 days, all BYL719-treated mutant mice were alive after 40 days and had an overtly normal appearance. Interruption of treatment after 40 days led to the rapid death of all mice. Administration of placebo or BYL719 7 days after Cre induction, when tissue abnormalities were already detected by MRI, resulted in improved survival in BYL719-treated mice. MRI after 12 days of treatment showed improvements in scoliosis, muscle hypertrophy, and vessel malformations. To more faithfully reproduce the lower mosaicism observed in patients, Venot et al. (2018) used a single dose of 4mg/kg of tamoxifen to induce Cre recombination. These mice survived for 2 months and then died with multiple phenotypic abnormalities including asymmetrical overgrowth of extremities, disseminated voluminous tumors, and visible subcutaneous vascular abnormalities. Histologic examination revealed the same lesions observed in human PIK3CA-related overgrowth. Treatment of these mice with BYL719 after lesions were clinically visible resulted in reduction and disappearance of all visible tumors within 2 weeks, with body weight loss. Notably, withdrawal of BYL719 led to recurrence of tumors, vascular malformations, and asymmetric extremity hypertrophy within 4 weeks.
Kurek et al. (2012) used massively parallel sequencing to search for somatic mosaic mutations in fresh, frozen, or fixed archival tissue from 6 patients with CLOVE syndrome and identified 3 different missense mutations in the PIK3CA gene (171834.0001, 171834.0009, and 171834.0010), with mutant allele frequencies ranging from 3 to 30% in affected tissue from multiple embryonic lineages. Noting that the 3 mutations had previously been identified in cancer cells, in which they increase phosphoinositide-3-kinase activity, Kurek et al. (2012) concluded that CLOVE syndrome is caused by postzygotic activating mutations in PIK3CA, and hypothesized that the low rate of malignant transformation in patients with CLOVE syndrome is due to the low level of endogenous PIK3CA expression in most cells. The authors also found somatic mosaicism for a PIK3CA mutation (171834.0001) in 3 patients who had been diagnosed with Klippel-Trenaunay-Weber syndrome (149000), an overgrowth syndrome with features overlapping those of CLOVE syndrome.
Lindhurst et al. (2012) performed exome sequencing of DNA from unaffected and affected cells from an individual with an unclassified syndrome of congenital progressive segmental overgrowth of fibrous and adipose tissue and bone and identified the cancer-associated mutation H1047L (171834.0002) in the PIK3CA gene only in affected cells, with mutation burdens determined to be from 8% to 39%. Sequencing of PIK3CA in 10 additional individuals with overlapping syndromes identified either the H1047L alteration or another cancer-associated alteration, H1047R (171834.0001), in 9. The H1047R variant was identified in 7 of the 9 affected individuals, with mutation burdens ranging from less than 1% to 35% in affected tissues and fibroblast cultures. The H1047L variant was identified in 2 of the 9 individuals, with mutation burdens ranging from 4% to 49%. Mutations were absent in blood and unaffected tissues from 9 of the affected individuals, from both parents of 6 of these individuals, and from 51 cell or tissue control samples. The syndrome described as 'unclassified' by Lindhurst et al. (2012) had features of CLOVE syndrome.
Sapp et al. (2007) stated that they proposed the name CLOVE syndrome on a heuristic basis. They selected the acronym because one of its definitions is a Middle English word for weight, being about 8 pounds.
Alomari (2009) proposed the acronym CLOVES syndrome to emphasize the association of this syndrome with major skeletal/scoliosis and spinal abnormalities.
Alomari, A. I. Characterization of a distinct syndrome that associates complex truncal overgrowth, vascular, and acral anomalies: a descriptive study of 18 cases of CLOVES syndrome. Clin. Dysmorph. 18: 1-7, 2009. [PubMed: 19011570] [Full Text: https://doi.org/10.1097/MCD.0b013e328317a716]
Atalar, M. H., Cetin, A., Kelkit, S., Buyukayhan, D. Giant fetal axillo-thoracic cystic hygroma associated with ipsilateral foot anomalies. Pediatr. Int. 48: 634-637, 2006. [PubMed: 17168988] [Full Text: https://doi.org/10.1111/j.1442-200X.2006.02263.x]
Biesecker, L. G., Peters, K. F., Darling, T. N., Choyke, P., Hill, S., Schimke, N., Cunningham, M., Meltzer, P., Cohen, M. M., Jr. Clinical differentiation between Proteus syndrome and hemihyperplasia: description of a distinct form of hemihyperplasia. Am. J. Med. Genet. 79: 311-318, 1998. [PubMed: 9781913] [Full Text: https://doi.org/10.1002/(sici)1096-8628(19981002)79:4<311::aid-ajmg14>3.0.co;2-u]
Eldredge, P. M. S., Munoz, G. S., Ruiz, S. Sindrome de Proteus: a proposito de un caso clinico. Rev. Hosp. de Ninos Buenos Aires 35: 127-130, 1993.
Gucev, Z. S., Tasic, V., Jancevska, A., Konstantinova, M. K., Pop-Jordanova, N., Trajkovski, Z., Biesecker, L. G. Congenital lipomatosis overgrowth, vascular malformations, and epidermal nevi (CLOVE) syndrome: CNS malformations and seizures may be a component of this disorder. Am. J. Med. Genet. 146A: 2688-2690, 2008. [PubMed: 18816642] [Full Text: https://doi.org/10.1002/ajmg.a.32515]
Jamis-Dow, C. A., Turner, J., Biesecker, L. G., Choyke, P. L. Radiologic manifestations of Proteus syndrome Radiographics 24: 1051-1068, 2004. [PubMed: 15256628] [Full Text: https://doi.org/10.1148/rg.244035726]
Kurek, K. C., Luks, V. L., Ayturk, U. M., Alomari, A. I., Fishman, S. J., Spencer, S. A., Mulliken, J. B., Bowen, M. E., Yamamoto, G. L., Kozakewich, H. P. W., Warman, M. L. Somatic mosaic activating mutations in PIK3CA cause CLOVES syndrome. Am. J. Hum. Genet. 90: 1108-1115, 2012. [PubMed: 22658544] [Full Text: https://doi.org/10.1016/j.ajhg.2012.05.006]
Lindhurst, M. J., Parker, V. E. R., Payne, F., Sapp, J. C., Rudge, S., Harris, J., Witkowski, A. M., Zhang, Q., Groeneveld, M. P., Scott, C. E., Daly, A., Huson, S. M., and 14 others. Mosaic overgrowth with fibroadipose hyperplasia is caused by somatic activating mutations in PIK3CA. Nature Genet. 44: 928-933, 2012. [PubMed: 22729222] [Full Text: https://doi.org/10.1038/ng.2332]
McCall, S., Ramzy, M. I., Cure, J. K., Pai, G. S. Encephalocraniocutaneous lipomatosis and the Proteus syndrome: distinct entities with overlapping manifestations. Am. J. Med. Genet. 43: 662-668, 1992. [PubMed: 1621755] [Full Text: https://doi.org/10.1002/ajmg.1320430403]
Ram, S. P., Noor, A. R. Neonatal Proteus syndrome. (Letter) Am. J. Med. Genet. 47: 303 only, 1993. [PubMed: 8213925] [Full Text: https://doi.org/10.1002/ajmg.1320470233]
Sapp, J. C., Turner, J. T., van de Kamp, J. M., van Dijk, F. S., Lowry, R. B., Biesecker, L. G. Newly delineated syndrome of congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE syndrome) in seven patients. Am. J. Med. Genet. 143A: 2944-2958, 2007. [PubMed: 17963221] [Full Text: https://doi.org/10.1002/ajmg.a.32023]
Venot, Q., Blanc, T., Rabia, S. H., Berteloot, L., Ladraa, S., Duong, J.-P., Blanc, E., Johnson, SC., Hoguin, C., Boccara, O., Sarnacki, S., Boddaert, N., and 24 others. Targeted therapy in patients with PIK3CA-related overgrowth syndrome. Nature 558: 540-546, 2018. Note: Erratum: Nature 568: E6, 2019. [PubMed: 29899452] [Full Text: https://doi.org/10.1038/s41586-018-0217-9]