Costello syndrome: report of six patients including one with an embryonal rhabdomyosarcoma

Costello syndrome: Clinical phenotype, genotype, and management guidelines

Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence-based guidelines due to the lack of data for this rare condition.

Retinal dystrophy in two boys with Costello syndrome due to the HRAS p.Gly13Cys mutation

Features of Costello Syndrome, a systemic disorder caused by germline mutations in the proto-oncogene HRAS from the RAS/MAPK pathway, include failure-to-thrive, short stature, coarse facial features, cardiac defects including hypertrophic cardiomyopathy, intellectual disability, and predisposition to neoplasia. Two unrelated boys with Costello syndrome and an HRAS mutation (p.Gly13Cys) are presented with their ophthalmologic findings. Both had early symptoms of nystagmus, photophobia, and vision abnormalities. Fundus examination findings of retinal dystrophy were present at age 3 years. Both boys have abnormal electroretinograms with reduced or undetectable rod responses along with reduced cone responses consistent with rod-cone dystrophy. Our observations suggest that early ophthalmic examination and re-evaluations are indicated in children with Costello syndrome.

Costello Syndrome and Umbilical Ligament Rhabdomyosarcoma in Two Pediatric Patients: Case Reports and Review of the Literature

Costello syndrome is caused by heterozygous de novo missense mutations in the protooncogene HRAS with tumor predisposition, especially rhabdomyosarcoma. We here report two pediatric patients with Costello syndrome and umbilical ligament rhabdomyosarcoma. A review of the literature published in English in MEDLINE from January 1971 to June 2016 using the search terms “Costello syndrome” and “rhabdomyosarcoma” was performed, including two new cases that we describe. Twenty-six patients with Costello syndrome and rhabdomyosarcoma were recorded with mean age of diagnosis of 2 years and 8 months. The most common tumor location was the abdomen/pelvis, including four out of ten of those in the umbilical ligament. The most common histological subtype was embryonal rhabdomyosarcoma. Overall survival was 43%. A total of 17 rhabdomyosarcomas in pediatric patients arising in the umbilical ligament were recorded with mean age of diagnosis of 3 years and 4 months. Overall survival was 69%. Costello syndrome is a poorly known disorder in pediatric oncology but their predisposition to malignancies implies the need for a new perspective on early diagnosis and aggressive medical and surgical treatment.

Rhabdomyosarcoma of the head and neck in children

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. It is localized in the head and neck region in 40% of cases. Treatment of RMS is complex, including multi-drug chemotherapy, radiotherapy and surgery. The progress that has been accomplished in oncology in recent decades significantly improved outcomes. The 5-year survival rate raised from 25% in 1970 to 73% in 2001, according to IRS-IV data. The outcome is influenced by primary tumor localization, clinical staging, histological tumor type and age at the moment of diagnosis. The relatively rare incidence of these tumors resulted in difficulties in creating more standardized therapeutic protocols. Comparison of outcomes in large patients groups led to an increase in the number of patients with complete remission. Although survival rates of RMS patients have improved, searching for new therapeutic modalities and substances is still essential to improve outcomes in cases of more advanced stages and unfavorable tumor localizations.

Perinatal features of the RASopathies: Noonan syndrome, cardiofaciocutaneous syndrome and Costello syndrome

The RASopathies are a family of developmental disorders caused by heritable defects of the RAS/MAPK signaling pathway. While the postnatal presentation of this group of disorders is well known, the prenatal and neonatal findings are less widely recognized. We report on the perinatal presentation of 10 patients with Noonan syndrome (NS), nine with Cardiofaciocutaneous syndrome (CFCS) and three with Costello syndrome (CS), in conjunction with the results of a comprehensive literature review. The majority of perinatal findings in NS, CS, and CFCS are shared: polyhydramnios; prematurity; lymphatic dysplasia; macrosomia; relative macrocephaly; respiratory distress; hypotonia, as well as cardiac and renal anomalies. In contrast, fetal arrhythmia and neonatal hypoglycemia are relatively specific to CS. NS, CS, and CFCS should all be considered as a possible diagnosis in pregnancies with a normal karyotype and ultrasound findings of a RASopathy. Recognition of the common perinatal findings of these disorders should facilitate both their prenatal and neonatal diagnosis.

Prenatal features of Costello syndrome: ultrasonographic findings and atrial tachycardia

OBJECTIVE

Delineate prenatal features of Costello syndrome (caused by HRAS mutations), which consists of mental retardation, facial, cardiovascular, skin, and musculoskeletal anomalies, and tumor predisposition.

METHODS

Literature and new cases classified as Group I (pre-HRAS), Group II (HRAS confirmed), and Group III (HRAS confirmed in natural history study, plus three contributed cases).

RESULTS

Polyhydramnios occurred in most (mean 79%) pregnancies of cases in Groups I (98), II (107), and III (17); advanced paternal age and prematurity were noted in approximately half. Less frequent were nuchal thickening, ascites, shortened long bones, abnormal hand posture, ventriculomegaly, macrosomia, and macrocephaly. Fetal arrhythmia occurred in nine cases (six supraventricular or unspecified tachycardia, one unspecified arrhythmia, and two premature atrial contractions, PACs); excluding three new cases and two with PACs, the estimated prenatal frequency is 4/222 (2%).

CONCLUSION

Costello syndrome can be suspected prenatally when polyhydramnios is accompanied by nuchal thickening, hydrops, shortened long bones, abnormal hand posture, ventriculomegaly, large size, and macrocephaly, and especially fetal atrial tachycardia. Consideration should be given for timely prenatal diagnostic studies for confirmative HRAS gene mutations and for maternal treatment of serious fetal arrhythmia.

Leukemia in Cardio-facio-cutaneous (CFC) syndrome: a patient with a germline mutation in BRAF proto-oncogene

Cardio-facio-cutaneous (CFC) syndrome is a multiple congenital anomaly/mental retardation syndrome characterized by a distinctive facial appearance, ectodermal abnormalities, and heart defects. Clinically, it overlaps with both Noonan syndrome and Costello syndrome, which are caused by mutations in 2 genes that encode molecules of the RAS/MAPK (mitogen activated protein kinase) pathway (PTPN11 and HRAS, respectively). Recently, mutations in KRAS, BRAF, and MEK1/2 have been identified in patients with CFC syndrome. Somatic mutations in KRAS and BRAF have been identified in various tumors. In contrast, the association with malignancy has not been noticed in CFC syndrome. Here we report a 9-year-old boy diagnosed with CFC syndrome and acute lymphoblastic leukemia. Sequencing analysis of the entire coding region of KRAS and BRAF showed a de novo germline BRAF E501G (1502A-->G) mutation. Molecular diagnosis and careful observations should be considered in children with CFC syndrome because they have germline mutations in proto-oncogenes and might develop malignancy.

Genotype-phenotype correlation in Costello syndrome: HRAS mutation analysis in 43 cases

BACKGROUND

Costello syndrome (CS) is a rare multiple congenital abnormality syndrome, associated with failure to thrive and developmental delay. One of the more distinctive features in childhood is the development of facial warts, often nasolabial and in other moist body surfaces. Individuals with CS have an increased risk of malignancy, suggested to be about 17%. Recently, mutations in the HRAS gene on chromosome 11p13.3 have been found to cause CS.

METHODS

We report here the results of HRAS analysis in 43 individuals with a clinical diagnosis of CS.

RESULTS

Mutations were found in 37 (86%) of patients. Analysis of parental DNA samples was possible in 16 cases for both parents and in three cases for one parent, and confirmed the mutations as de novo in all of these cases. Three novel mutations (G12C, G12E, and K117R) were found in five cases.

CONCLUSIONS

These results confirm that CS is caused, in most cases, by heterozygous missense mutations in the proto-oncogene HRAS. Analysis of the major phenotypic features by mutation suggests a potential correlation between malignancy risk and genotype, which is highest for patients with an uncommon (G12A) substitution. These results confirm that mutation testing for HRAS is a reliable diagnostic test for CS.

Behavioral and temperamental features of children with Costello syndrome

Costello syndrome (CS) is a rare genetic condition due to germline mutations in HRAS proto-oncogene and characterized by increased birth weight, postnatal growth retardation, distinctive facial appearance, typical medical problems (including feeding problems in the neonatal period), cutaneous anomalies, and developmental delay. Outgoing personality has often been noted in case reports, but few studies have focused specifically on the behavioral aspects of CS. A preliminary survey described irritability in younger patients with improvement between age 2 and 4, but a standardized psychometric tool was not used. A second study using the Child Behavior Checklist (CBCL) showed relatively high (albeit subclinical) levels of internalizing problems. These descriptive investigations lacked a control group. We describe a comparative survey to evaluate the behavioral and temperamental features of children with CS. We conducted a cross-sectional assessment using the CBCL and the Emotionality, Activity, Shyness, Sociability (EAS) temperament questionnaire to evaluate behavior and temperament in 11 CS children (2 years 5 months to 9 years) comparing them to 33 gender- and age-matched children without disability. The results suggest that the high levels of internalizing problems found before age 4 in CS patients might decrease with age. They also point to possible "hyperemotionality." Further studies using a larger sample size and IQ-matched control groups are needed to more accurately characterize individuals with this rare syndrome.

Tumor predisposition in Costello syndrome

Costello syndrome (CS) is a rare congenital anomaly syndrome. Although it may be classified as an "overgrowth" syndrome due to slightly increased birth weight and relative macrocephaly, it is characterized by severe postnatal failure to thrive and short stature. Patients with CS have an increased risk for malignant tumors, a hallmark of several model overgrowth syndromes. The most common tumor in CS is rhabdomyosarcoma (RMS), followed by neuroblastoma and bladder carcinoma. The occurrence of bladder carcinoma in adolescents is distinctly unusual as this is typically a neoplasm of older adults and is not seen with increased frequency in other tumor predisposition syndromes. The increased tumor frequency in CS led to the proposal of a screening protocol, consisting of abdominal and pelvic ultrasounds, and urine studies for catecholamine metabolites and hematuria. It has since become apparent that patients with CS have an increased excretion of catecholamine metabolites in urine without the presence of an identifiable catecholamine secreting tumor. Thus, the urine assay for catecholamines is unhelpful as a screening test for neuroblastoma and should not be used in this population. The benefit of abdominal and pelvic ultrasound and urinalysis for hematuria as screening tests remains to be shown. A timely diagnosis of CS is a necessary prerequisite for awareness of the increased tumor risk. Once a malignancy has been identified, treatment should follow standard protocols. Additional medical problems characteristic for CS, such as hypertrophic cardiomyopathy and arrhythmia, need to be considered and addressed appropriately.

Parameningeal rhabdomyosarcoma in a patient with Costello syndrome

Costello syndrome, a rare entity with multiple congenital anomalies, has been associated with a high incidence of benign and malignant tumors, particularly rhabdomyosarcoma. Although the head and neck is the most common site for rhabdomyosarcomas in children, only one other case in the literature has been reported of a head and neck rhabdomyosarcoma in a Costello patient. The authors describe a 3-year-old with a parameningeal infratemporal fossa rhabdomyosarcoma. Management is discussed with particular attention to the difficulties encountered due to the congenital heart abnormalities associated with the syndrome.

Further delineation of the behavioral and neurologic features in Costello syndrome

To describe clinical and neurodevelopmental phenotypes of Costello syndrome, we performed a retrospective review of the clinical records and findings in 10 children with Costello syndrome. All patients showed significant postnatal growth retardation and severe feeding difficulties leading to failure to thrive from early infancy. All required tube feeding and some needed high-calorie formulas for variable periods. Developmental quotients/IQs in seven children were 50 or less, and three were in the mildly retarded range. Five had seizures. Remarkable manifestations not previously reported were the characteristic behavior in infancy. Although happy and sociable personality was always emphasized in the genetic literature, all children showed significant irritability, including hypersensitivity to sound and tactile stimuli, sleep disturbance, and excess shyness with strangers in infancy. Those symptoms usually disappeared around age 2-4 years. Other clinical signs included cardiac abnormalities (8), musculoskeletal abnormalities (10), ophthalmological manifestations (5), increased urinary vanillymandelic acid (VMA) and homovanillic acid (HVA) (3), rhabdomyosarcoma (1), laryngomalacia (1), and cryptorchidism (1). Only three girls had papillomata. Family histories were negative for Costello syndrome. In conclusion, we confirm the wide spectrum of mental function in patients with Costello syndrome, which ranges from severe to mild. During infancy Costello syndrome showed remarkable irritability with severe feeding problems, which attributes significant difficulties to the parents of affected children.

Costello syndrome: an overview

The Costello syndrome is characterized by prenatally increased growth, postnatal growth retardation, coarse face, loose skin resembling cutis laxa, nonprogressive cardiomyopathy, developmental delay, and a outgoing, friendly behavior. Patients can develop papillomata, especially around the mouth, and have a predisposition for malignancies (mainly abdominal and pelvic rhabdomyosarcoma in childhood). Costello syndrome is likely to be an autosomal dominant disorder. The pathogenesis is unclear, but there are many clues for a disturbed elastogenesis, possibly through a disturbed elastin-binding protein reuse by chondroitin sulfate-bearing proteoglycans accumulation. A review of the findings in the 73 patients that have been described in sufficient detail is provided.

[Costello syndrome: clinical aspects and tumor risk]

Costello syndrome is a sporadic development anomaly suggesting a genetic determinism. Main features include characteristic facial features, mental retardation, growth retardation, cutis laxa, heart malformation, and peri-orificial papillomata. In previous reported cases, the frequency of tumors is 15%, which argues for a screening protocol. The occurrence of a tumor in a child with growth retardation and cutis laxa must be reminiscent of Costello syndrome. The determinism of this syndrome is still unknown, and the hypothesis of an inactivation of a tumor suppressor gene is to be considered.

Further delineation of cardiac abnormalities in Costello syndrome

We review the cardiac abnormalities in 94 patients (27 new, 67 literature) with Costello syndrome, an increasingly recognized syndrome consisting of increased birth weight, postnatal growth retardation, and distinctive facial, skin, and musculoskeletal features (MIM 218040). A cardiac abnormality was found in 59 (63%) patients, with each of three categories occurring in approximately one-third of patients. A cardiovascular malformation (CVM) was noted in 30%, typically pulmonic stenosis (46% of those with a CVM). Cardiac hypertrophy was reported in 34%, which involved the left ventricle in 50% and was usually consistent with classic hypertrophic cardiomyopathy (HCM). A variety of rhythm disturbances were reported in 33%. Most (74%) were atrial tachycardia that was reported as supraventricular, chaotic, multifocal, or ectopic. Of 31 patients with a rhythm abnormality, 22 (68%) had an additional abnormality, i.e., CVM (4), cardiac hypertrophy (12), or both (6). Nine patients had isolated dysrhythmia, five (56%) of whom died. All of the 12 (13%) patients who died had a cardiac abnormality. One patient died of embryonal rhabdomyosarcoma, but in the remainder, a cardiac cause of death could not be disproved. All patients with Costello syndrome need a baseline cardiology evaluation with echocardiography and Holter monitoring. Additional prospective evaluations, even in patients without apparent cardiac abnormalities, would be prudent, although data are insufficient to propose a specific schedule.

Prenatal findings in a monozygotic twin pregnancy with Costello syndrome

This report describes the prenatal findings in monozygotic twins with Costello syndrome. At 16 weeks one twin had 9 mm of nuchal oedema: coarctation of the aorta was diagnosed after birth. At 22(5/7) weeks relative macrocephaly, mild pyelectasia and moderate polyhydramnios were noted in both twins. In the following 4 weeks the polyhydramnios increased significantly without visualisation of filling of the stomach. Between 27(5/7) and 30(2/7) weeks a total of 9 l amniotic fluid was drained and at 30(4/7) weeks prelabor premature rupture of membranes (PPROM) occurred followed by premature labor and delivery. The neonatal period was complicated by growth retardation, deglutition problems, hypotonia, cardiac and respiratory problems. Both twins died on Day 57 because of respiratory insufficiency.

Five additional Costello syndrome patients with rhabdomyosarcoma: proposal for a tumor screening protocol

We report five new cases of rhabdomyosarcoma (RMS) in Costello syndrome. These cases, combined with those previously reported, increase the number of solid tumors to 17 (10 RMSs, 3 neuroblastomas, 2 bladder carcinomas, 1 vestibular schwannoma, 1 epithelioma), in at least 100 known Costello syndrome patients. Despite possible ascertainment bias, and the incomplete identification of all Costello syndrome patients, the tumor frequency could be as high as 17%. This is comparable to the 7-21% frequency of solid tumors in Beckwith-Wiedemann syndrome (BWS), and may justify tumor screening. Based on the recommendations for screening BWS patients, we propose a screening protocol consisting of ultrasound examination of the abdomen and pelvis every 3-6 months until age 8-10 years for RMS and abdominal neuroblastoma; urine catecholamine metabolite analysis every 6-12 months until age 5 years for neuroblastoma; and urinalysis for hematuria annually for bladder carcinoma after age 10 years. These recommendations may need to be modified, as new information becomes available. Potential criticism of the tumor screening protocol concerns the lack of evidence for improved outcome, and possible overestimation of the tumor risk. The ability of RMSs to occur at various sites complicates tumor screening, but 8 of the 10 RMSs in Costello syndrome patients originated from the abdomen, pelvis and urogenital area. Prior diagnosis of Costello syndrome is a prerequisite for the implementation of any screening protocol. The diagnosis of Costello syndrome should also be considered in individuals with RMS and physical findings suggestive of Costello syndrome.