Transmission of Proteus syndrome from father to son?

Hypertrichotic patches as a mosaic manifestation of Proteus syndrome

BACKGROUND

Proteus syndrome is an overgrowth disorder caused by a mosaic activating AKT1 variant. Hair abnormalities in Proteus syndrome have rarely been reported, and frequencies of such findings have not been elucidated.

OBJECTIVE

To define the types and frequencies of hair findings in individuals with Proteus syndrome.

METHODS

A cross-sectional study was conducted of individuals with clinical features of Proteus syndrome and a confirmed pathogenic variant in AKT1 evaluated between November 1996 and June 2019 at the National Institutes of Health Clinical Center. Medical records were reviewed for patterning, density, and color of hair on the body and scalp.

RESULTS

Of 45 individuals evaluated, 29 (64%) had asymmetric hypertrichosis on the body. This included unilateral blaschkoid hypertrichotic patches overlying normal skin or epidermal nevi in 16 (36%), unilateral nonblaschkoid hypertrichotic patches in 11 (24%), and unilateral limb hypertrichosis in 10 (22%). Diffuse, scattered, or patchy changes in scalp hair density or color were present in 11 individuals (24%).

LIMITATIONS

The retrospective, observational design, and limited longitudinal follow-up.

CONCLUSIONS

Asymmetric variations in hair distribution, thickness, length, and color contribute to the overall mosaic appearance of the skin in Proteus syndrome, an observation that provides novel insights into the role of phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling in skin appendage development.

A review of vascular anomalies: genetics and common syndromes

Vascular tumors and malformations are unique in that affected cells exhibit disrupted angiogenesis. The current treatment options often yield suboptimal results. New insight into the genetics and molecular basis of vascular anomalies may pave the way for potential development of targeted therapy. The authors review the genetic and molecular basis of vascular anomalies and common associated syndromes.

Dentomaxillofacial imaging in Proteus syndrome

Proteus syndrome is a rare condition that involves atypical growth of the bones, skin and head and a variety of other symptoms. Only a few authors have reported on the craniofacial manifestations so far. The authors present a case of a 7-year-old girl with Proteus syndrome in which the facial skeleton showed unilateral overgrowth. The analysis of the radiological evaluation revealed a bialveolar prognathism, a skeletal class III, a dolicocephalic growth pattern and a left convex face scoliosis. On the left side, the lesser wing of the sphenoid was elevated and the ethmoidal cell complex was hypertrophic. The left ramus and body of the mandible were enlarged. The asymmetric dental development with a precocious dental age on the affected side was the most striking feature on the panoramic view. Early diagnosis and therapy depend on clinical evaluation and imaging. Therefore, further evaluations on the craniofacial features of patients with Proteus syndrome are necessary in order to establish a list of characteristic symptoms.

Reassessment of the Proteus syndrome literature: application of diagnostic criteria to published cases

The medical care of patients affected by rare disorders depends heavily on experiences garnered from prior cases, including those patients evaluated by the treating physician and those published in the medical literature. The utility of published cases is wholly dependent upon accurate diagnosis of those patients. In our experience, the rate of misdiagnosis in Proteus syndrome (PS) is high. Diagnostic criteria have been published, but these criteria have not been applied consistently and were published after many case reports appeared in the literature. We reviewed 205 cases of individuals reported to have PS in the literature and three of us independently applied the diagnostic criteria to these case reports. Our initial diagnostic congruence was 97.1% (199/205); the discrepancies in six cases were easily resolved. Only 97 (47.3%) of reported cases met the diagnostic criteria for PS; 80 cases (39%) clearly did not meet the criteria; and although 28 cases (13.7%) had features suggestive of PS, there were insufficient clinical data to make a diagnosis. Reported cases that met the PS criteria had a higher incidence of premature death, and other complications (scoliosis, megaspondyly, central nervous system abnormalities, tumors, otolaryngologic complications, pulmonary cystic malformations, dental and ophthalmogic complications) compared to those in the non-Proteus group. The cases that met the criteria were more often male, which has implications for hypotheses regarding the etiology and pathophysiology of PS. We also studied the attributes that led authors to conclude the reported patients had PS when we concluded they did not. We found that two of the diagnostic criteria (disproportionate overgrowth and connective tissue nevi) were often misinterpreted. In PS, the abnormal growth is asymmetric, distorting, relentless, and occurred at a faster rate compared to the rest of the body. Furthermore, PS was associated with irregular and disorganized bone, including hyperostoses, hyperproliferation of osteoid with variable calcification, calcified connective tissue, and elongation of long bones with abnormal thinning. In contrast, non-Proteus cases displayed overgrowth that was asymmetric but grew at a rate similar to the growth found in unaffected areas of the body. Also, the overgrowth in non-Proteus cases was associated with normal or enlarged bones together with ballooning of the overlying soft tissues. Taken together, these data show that (1) PS diagnostic criteria sort individuals with asymmetric overgrowth into distinct groups; (2) individuals with PS were more likely to have serious complications; (3) PS affects more males than females; and 4) the published diagnostic criteria are useful for clinical care and research. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

[Proteus syndrome: report of two cases]

Proteus syndrome is a complex disorder, consisting of mesodermal and skeletal malformations as well as hamartomatous overgrowth. It is characterized by highly variable presentation and mosaic-pattern lesions. The two cases described herein illustrate the wide polymorphism of this syndrome. The second case also had a pubic fracture, which we have not previously seen reported in the medical literature on Proteus syndrome.

Principles for the surgical management of patients with Proteus syndrome and patients with overgrowth not meeting Proteus criteria

BACKGROUND

Proteus syndrome is a rare, sporadic disorder consisting of disproportionate overgrowth of multiple tissues, vascular malformations, and connective tissue or epidermal nevi. Patients with Proteus syndrome present with diverse and variable phenotypes because of the syndrome's mosaic pattern of distribution.

METHODS

Eighty patients with Proteus syndrome, satisfying published diagnostic criteria, and 51 patients with overgrowth not meeting Proteus criteria were identified from the literature. Three additional patients, one patient with Proteus syndrome and 2 patients with overgrowth, were treated at the author's institutions and are discussed in detail. All nonorthopedic and noncutaneous surgical interventions were reviewed.

RESULTS

Fourteen genitourinary, 9 gastrointestinal, and 5 otolaryngologic operations were performed on patients with Proteus syndrome. Six genitourinary, 5 gastrointestinal, and 2 otolaryngologic operations were performed on patients with overgrowth not meeting Proteus criteria. Eight patients with Proteus syndrome and 4 patients with overgrowth experienced thoracic manifestations, generally diffuse cystic pulmonary lesions, but only 1 of 12 underwent surgical treatment.

CONCLUSIONS

Patients with visceral manifestations of either Proteus syndrome or overgrowth not meeting Proteus criteria should be treated in a similar manner. Lesions involving the ovaries and testes, because of the high incidence of neoplasm, should be managed aggressively. Gastrointestinal and renal lesions may be managed conservatively with frequent follow-up to minimize abdominal explorations. All patients undergoing surgery should have a thorough preoperative assessment of their airway and pulmonary reserve because of the relatively high frequency of tonsillar hypertrophy and pulmonary cystic involvement.

A novel ophthalmic presentation of the Proteus syndrome

PURPOSE

To report a patient with the Proteus syndrome who had ocular complications not previously described in the literature.

DESIGN

Single observational case report.

METHODS

Retrospective review of the medical record and review of the literature.

RESULTS

The 26-year-old man has systemic features fulfilling the diagnostic criteria for the Proteus syndrome. His ocular abnormalities are myopia, mild calcific band keratopathy, cataract, abnormal vitreous structure, vitreous hemorrhage, a large chorioretinal mass, and a resolved serous retinal detachment.

CONCLUSIONS

Ocular complications are frequently reported in patients with the Proteus syndrome. Few of the patients reported in the literature have had comprehensive ocular examination by an ophthalmologist. Our patient is unique because he has been examined by ophthalmologists from childhood, and it is clear that the ocular findings may change with time. As far as we are aware, calcific band keratopathy, abnormal vitreous structure, and chorioretinal hamartoma associated with serous retinal detachment and vitreous hemorrhage have not previously been described.

Proteus syndrome: clinical and surgical aspects

The authors report a new case of Proteus syndrome with delayed diagnosis and they discuss the place of surgery in this syndrome.

Ocular manifestations in Proteus syndrome

We report on the ocular manifestations of a Proteus syndrome patient. Several of the manifestations are due to severe maldevelopment and malfunction of the neuroretina including strabismus, nystagmus, high myopia, and retinal pigmentary abnormalities. In reviewing the literature, strabismus and epibulbar tumors were recorded most commonly. Some articles about presumed Proteus syndrome are spurious; these have not been included here. Also, because of anecdotal and nonsystematic study of the eye and because of the ascertainment bias inherent in literature reports, numbers of cases of each ocular manifestation have not been tabulated.

Paradominant inheritance, a hypothesis explaining occasional familial occurrence of sporadic syndromes

Heterozygous individuals carrying a "paradominant" mutation, as a rule, are phenotypically normal. Therefore, the mutation can be transmitted unperceived through many generations. The trait becomes manifest when a somatic mutation occurs during embryogenesis giving rise to loss of heterozygosity and forming a mutant cell population, being either homozygous or hemizygous for the mutation. This concept explains the occasional familial occurrence of usually sporadic traits like the Klippel-Trenaunay syndrome and others.

Cutaneous mosaicism of lethal mutations

The concept of autosomal lethal genes surviving only in a mosaic state was proposed by Happle to explain the genetic basis of several syndromes characterized by (almost always) sporadic occurrence, distribution of lesions in a scattered or asymmetrical pattern, variable extent of involvement, lack of diffuse involvement of entire organs, and equal sex ratio. The mosaic may either arise from a gametic half-chromatid mutation or from an early postzygotic mutation. The purpose of this article is to review current knowledge of the genetics and cutaneous manifestations of some of the birth defects to which the lethal gene concept is thought to apply: the Schimmelpenning (Feuerstein-Mims) syndrome, Proteus syndrome, encephalocraniocutaneous lipomatosis, Sturge-Weber and Klippel-Trenaunay syndrome, cutis marmorata teleangiectatica congenita (van Lohuizen syndrome), and neurocutaneous melanosis.

Proteus syndrome: diagnostic criteria, differential diagnosis, and patient evaluation

Proteus syndrome is a complex disorder comprising malformations and overgrowth of multiple tissues. The disorder is highly variable and appears to affect patients in a mosaic manner. This intrinsic variability has led to diagnostic confusion associated with a dearth of longitudinal data on the natural history of Proteus syndrome. To clarify some of these issues, a workshop on Proteus syndrome was held in March 1998 at the National Institutes of Health, and participants developed recommendations for diagnostic criteria, differential diagnosis, and guidelines for the evaluation of patients. This is a review of those recommendations.

Elattoproteus syndrome: delineation of an inverse form of Proteus syndrome

A 7-year-old boy had partial lipohypoplasia and patchy dermal hypoplasia involving large areas of his body. These areas of deficient growth were similar to those described in many cases of Proteus syndrome. Paradoxically, however, he had only few and rather mild lesions of disproportionate overgrowth. This unusual case is taken as a clue to postulate the Elattoproteus syndrome, an inverse form of Proteus syndrome. The paradoxical coexistence of hyperplastic and hypoplastic lesions may reflect a twin spot phenomenon. The patient would carry at the Proteus locus one allele giving rise to overgrowth of tissues (Pleioproteus allele--from Greek pleion, meaning plus), whereas the other allele would cause deficient growth of tissues (Elattoproteus allele--from Greek elatton, meaning minus). At an early stage of embryogenesis, somatic recombination would give rise to two different populations of cells homozygous for either allele. From a heuristic point of view, one may postulate the existence of the Elattoproteus syndrome, a purely inverse form of Proteus syndrome that would develop in the absence of the Pleioproteus allele.

Proteus syndrome with widespread portwine stain naevus

Proteus syndrome is a rare condition comprising asymmetrical overgrowth of different parts of the body in association with various cutaneous abnormalities. We describe a 3-year-old boy with Proteus syndrome, who presented with hemihypertrophy of the right leg, asymmetric macrodactyly, subcutaneous masses and a widespread portwine stain interspersed with angiokeratomas on the right leg, scrotum and on the middle and left side of the back. Doppler ultrasound of the right leg did not show hypercirculation, but did reveal the absence of the right superficial femoral vein.

Pathology of lipomatous lesions in Proteus syndrome

Proteus syndrome is an extremely rare, complex hamartomatous disorder with markedly variable clinical expression. We present a case of Proteus syndrome with multiple disfiguring soft tissue masses that were present since early childhood. The lesions involved predominantly the right side of the body and included scoliosis, macrodactyly, and limited hyperostosis in the right foot. There was no evidence of cranial or skin lesions. The patient underwent multiple resections of soft tissue masses, including an amputation of the right foot because of severe gait disturbance. All specimens exhibited lipomatous lesions that were probably hamartomatous rather than neoplastic. She carried a diagnosis of neurofibromatosis for more than a decade, but a re-evaluation of clinical features and pathological findings prompted the diagnosis of Proteus syndrome. We believe that a more informed evaluation of the pathology material may help to identify this rare entity.

Proteus syndrome: diagnosis in adulthood

We describe a 24-year-old woman with many of the classical features of the Proteus syndrome. In childhood she had undergone bilateral forefoot amputations because of massive bilateral cerebriform hypertrophy of the feet. Other features include abnormally large fingers on one hand, a lymphangioma circumscriptum, an epidermal naevus, prominent venous varicosities and scattered lipomas. The disorder occurs sporadically and is thought to be secondary to a postzygotic mutation that survives by mosaicism.

Non-operative management of a splenic laceration in a patient with the Proteus syndrome

An adult patient with the Proteus syndrome sustained a grade III splenic laceration after falling off a horse. Clinical features of this rare disorder include subcutaneous and visceral hamartomatous tumours. The patient also suffered from chronic intravascular coagulation associated with extensive haemangiomatosis (Kasabach-Merritt syndrome). Considering the visceral anomalies and abnormal coagulation, a non-operative approach was preferred despite considerable transfusion requirement, and the patient successfully underwent embolisation of the splenic artery. This is the first reported case of splenic injury in a patient with Proteus syndrome.

Hemihypertrophy, hemimegalencephaly, and polydactyly

We present clinical and neuropathological details of a patient with hemihypertrophy and hemimegalencephaly who may have Proteus syndrome. The observation of polysyndactyly in the case indicates either that polysyndactyly is a rare manifestation in Proteus syndrome, or that a separate condition, mimicking Proteus syndrome and pursuing a similar clinical course, might exist.

Lymphangiolipoma of the thoracic spine in a pediatric patient with Proteus syndrome

Proteus syndrome is a rare hamartomatous disorder involving macrodactyly, hemihypertrophy, and subcutaneous lymphangiomas; fewer than 25 cases have been reported worldwide. We report a case of a thoracic epidural lymphangiolipoma in a 5-year-old boy with Proteus syndrome. Computerized axial tomography (CT) of the thoracic spine revealed a left posterior mediastinal mass that extended into the spinal canal through adjacent neural foramina. No sign of spinal cord compression was observed despite the extensive volume of tumor within the spinal canal. Surgical debulking utilizing a T3-10 laminectomy resulted in gross total resection of the tumor. Microscopic examination of the surgical specimen revealed a lymphangiolipoma. No previous report of spinal cord involvement has been reported in this syndrome. A detailed discussion of the phenotypic features and probable mode of genetic transmission is included.

Proteus syndrome: association with gingival hyperplasia

A 9-year old Black boy with gigantism of the hands and feet, and recurrent gingival hyperplasia, diagnosed as Proteus syndrome is presented. The oral manifestations of this syndrome are described. To the best of our knowledge, this is the first reported case of gingival hyperplasia associated with Proteus syndrome.

Epidermal nevus syndromes

A clinical entity called "the epidermal nevus syndrome" does not exist. Rather, there are various epidermal nevus syndromes that can be distinguished by clinical, histopathological, and genetic criteria. In this review, five distinct epidermal nevus syndromes, recognizable by different types of associated epithelial nevi, are described. The Schimmelpenning syndrome is characterized by a sebaceous nevus associated with cerebral anomalies, coloboma, and lipodermoid of the conjunctiva. By contrast, cataracts are a prominent feature of the nevus comedonicus syndrome. The pigmented hairy epidermal nevus syndrome includes Becker nevus, ipsilateral hypoplasia of the breast, and skeletal defects such as scoliosis. In the Proteus syndrome, the associated epidermal nevus is of a flat, velvety, nonorganoid type. The CHILD syndrome occurs almost exclusively in girls. The associated CHILD nevus shows unique features such as a diffuse form of lateralization, ptychotropism, and microscopic changes of verruciform xanthoma. The five epidermal nevus syndromes differ in their genetic basis. The Schimmelpenning and nevus comedonicus syndromes are most likely nonhereditary traits. By contrast, the pigmented hairy epidermal nevus syndrome and the Proteus syndrome may be explained by paradominant inheritance. The CHILD syndrome is caused by an X-linked dominant mutation exerting a lethal effect on male embryos. A correct diagnosis of these phenotypes is important for both recognition and treatment of associated anomalies as well as for genetic counseling.

Proteus syndrome

A 10-month-old girl had macrodactyly, facial and extremity hemihypertrophy, plantar cerebriform hyperplasia, a subcutaneous mass on the back, macrocephaly, and lumbar kyphosis. These findings were diagnostic of Proteus syndrome. The clinical features, etiology, management, and points of differential diagnosis are discussed.

Growth hormone (GH), insulin-like growth factors (IGFs), and IGF-binding protein-3 (IGFBP-3) in a child with Proteus syndrome

Proteus syndrome is a congenital hamartomatous disorder characterized by partial overgrowth involving all germ layers. A somatic mutation model has been proposed since familial cases are extremely rare. We report on a 3-year-old girl with typical manifestations of Proteus syndrome, including local, asymmetric hypertrophy of various parts of the body. Total body length was reduced. Serum levels of IGF-I and especially IGF-II and their major growth hormone dependent binding protein (IGFBP-3) were significantly reduced, although growth hormone secretion after a pharmacological stimulus was normal. In vitro studies of fibroblasts derived from hypertrophied tissue showed normal IGF-I production and somewhat reduced IGF-II and IGFBP-3 production as compared to normal human skin fibroblasts. Affinity cross-linking experiments showed that fibroblasts of the affect tissue in Proteus syndrome produced an unusual pattern of IGF bindings proteins containing large amounts of an IGFBP with high affinity to IGF-II. The data suggest that IGF production is generally disturbed in Proteus syndrome with imbalanced levels of specific IGFBP in affected tissue.

Proteus syndrome: clinical evidence for somatic mosaicism and selective review

I report 2 unusual cases of Proteus syndrome that support the concept of somatic mosaicism. In one patient, a huge connective tissue nevus covered the chest and abdomen and hyperostoses of the calvaria were observed. In the other patient, linear verrucous epidermal nevi, epibulbar dermoids, and hyperostoses were found. No enlargement of the limbs or digits occurred and the plantar surfaces of the feet were normal. Selective aspects of Proteus syndrome not previously reviewed are also presented including: uncommon neoplasms; pulmonary and renal abnormalities; brain malformations; facial phenotype associated with seizures and severe mental deficiency; and types of abnormal growth in the craniofacial skeleton.

Ophthalmologic examination in the diagnosis of Proteus syndrome

PURPOSE

To describe the clinical features of Proteus syndrome, a rare recently recognized hamartoneoplastic malformation, with emphasis on the ocular findings.

METHODS

Complete physical and ocular examination of two new patients with Proteus syndrome.

RESULTS

The two reported cases illustrate the wide clinical polymorphism of Proteus syndrome and the overlap of its clinical manifestations with those of other overgrowth syndromes. Both patients had periorbital exostoses and epibulbar tumors. The ocular findings are compared with those in the literature.

CONCLUSION

Considering the paucity of information in the ophthalmic literature, this article explores the role of the ophthalmologist in diagnosing this rare entity.