Growth hormone replacement therapy in Costello syndrome

Dermatological manifestations in Costello syndrome: A prospective multicentric study of 31 HRAS-positive variant patients

BACKGROUND

Data on dermatological manifestations of Costello syndrome (CS) remain heterogeneous and lack in validated description.

OBJECTIVES

To describe the dermatological manifestations of CS; compare them with the literature findings; assess those discriminating CS from other RASopathies, including cardiofaciocutaneous syndrome (CFCS) and the main types of Noonan syndrome (NS); and test for dermatological phenotype-genotype correlations.

METHODS

We performed a 10-year, large, prospective, multicentric, collaborative dermatological and genetic study.

RESULTS

Thirty-one patients were enrolled. Hair abnormalities were ubiquitous, including wavy or curly hair and excessive eyebrows, respectively in 68% and 56%. Acral excessive skin (AES), papillomas and keratotic papules (PKP), acanthosis nigricans (AN), palmoplantar hyperkeratosis (PPHK) and 'cobblestone' papillomatous papules of the upper lip (CPPUL), were noted respectively in 84%, 61%, 65%, 55% and 32%. Excessive eyebrows, PKP, AN, CCPUL and AES best differentiated CS from CFCS and NS. Multiple melanocytic naevi (>50) may constitute a new marker of attenuated CS associated with intragenic duplication in HRAS. Oral acitretin may be highly beneficial for therapeutic management of PPHK. No significant dermatological phenotype-genotype correlation was determined between patients with and without HRAS c.34G>A (p.G12S).

CONCLUSIONS AND RELEVANCE

This validated phenotypic characterization of a large number of patients with CS will allow future researchers to make a positive diagnosis, and to differentiate CS from CFCS and NS.

Fatal leukodystrophy in Costello syndrome: a case report

BACKGROUND

Costello syndrome (CS) is a rare genetic condition characterized by dysregulation of the signaling pathway, phenotypic alteration due to fetal macrosomia or growth retardation, facial abnormalities, loose skin, cardiovascular abnormalities, and a variable degree of intellectual disability.

CASE PRESENTATION

We describe the case of a 20-month-old male patient with fetal macrosomia and polyhydramnios, presenting psychomotor development delay and growth limitation during the first months of life. CS was diagnosed at four months of age after detecting a variant of the HRAS gene c.35G > C (p.G12A). A clinical description of his condition was recorded throughout his life, including cardiovascular diseases, endocrine disorders, and recurrent infections. At 20 months of age, after presenting events of marked hypotonia and generalized seizures, brain magnetic resonance revealed symmetrical lesions of the infra- and supratentorial white matter in both cerebral hemispheres, which resulted in the diagnosis of cerebral leukodystrophy. The patient had a rapid and progressive deterioration that eventually led to death.

CONCLUSIONS

This is the first report of a case of CS in Peru. In addition, this is a case that presented with multisystemic conditions culminating in leukodystrophy, which is a rare event according to the literature.

Prevalence of gastrointestinal disorders in individuals with RASopathies: May RAS/MAP/ERK pathway dysfunctions be a model of neuropathic pain and visceral hypersensitivity?

RASopathies are a group of neurodevelopmental syndromes caused by germline variants in genes of the Ras/MAP/ERK pathway. Growth failure, neurological involvement, and pain represent the main features of these conditions. ERK signaling cascade plays a crucial role in nociception and visceral pain and it is likely implicated in the genesis of neuropathic pain and maintenance of altered pain states. We studied the prevalence of abdominal pain and functional gastrointestinal (GI) disorders in a large sample of individuals with RASopathies. A brief pain inventory questionnaire and semi-structured dedicated interview were used to investigate presence and localization of pain. A Rome IV questionnaire was used to screen for functional GI disorders. Eighty patients with clinical and molecular diagnoses of RASopathy were recruited (42 with Noonan syndrome; 17 with Costello Syndrome and 21 with cardio-facio-cutaneous syndrome). Overall, the prevalence of abdominal pain was 44% and prevalence of functional GI disorders was 78% with constipation, abdominal pain, and aerophagia being the most frequently detected ones. A significant association was found between pain and irritable bowel syndrome, functional constipation and aerophagia. Children with RASopathies have a high prevalence of functional gastrointestinal disorders. These children could represent a good in vivo model to study neuropathic pain, visceral hypersensitivity and gut-brain axis disorders.

Activation of the MAPK pathway (RASopathies) and partial growth hormone insensitivity

RASopathies are a heterogeneous group of syndromes caused by germline mutations in genes encoding components of the RAS/MAPK pathway. Postnatal short stature is a cardinal feature of the RASopathies. Although the pathophysiology of these conditions is not fully understood to date, growth hormone insensitivity is one possibility, based on the observation of low IGF-1 values, generally preserved GH secretion and suboptimal growth response to recombinant human GH therapy. In this review, we will discuss the clinical and experimental evidence of GH insensitivity in patients with Noonan syndrome and other RASopathies, as well as their molecular basis.

Autoimmune Thyroid Disease in Specific Genetic Syndromes in Childhood and Adolescence

Autoimmune thyroid disease (ATD) is the most frequent cause of acquired thyroid dysfunction, most commonly presenting either as Hashimoto's thyroiditis or Graves' Disease. Hashimoto's thyroiditis is characterized by the presence of thyroid-specific autoantibodies, more commonly anti-thyroperoxidase antibodies in the serum and the typical inhomogeneous echostructure of the thyroid on a thyroid ultrasound examination. Hashimoto's thyroiditis can for a long time be accompanied by normal thyroid function and hypothyroidism can only progressively be established. Graves' disease is much less frequent in childhood and adolescence and presents with overt hyperthyroidism. After the onset of puberty, ATD affects females with a higher incidence than males, while during the prepubertal period there is not such a clear preponderance of affected females. ATD can occur either isolated or in the context of other autoimmune disorders, such as type 1 Diabetes mellitus (T1D), celiac disease, alopecia areata, vitiligo, etc. Especially at the pediatric age, a higher incidence of ATD is also observed in the context of specific genetic syndromes, such as trisomy 21 (Down syndrome), Klinefelter syndrome, Turner syndrome, or 22q11.2 deletion syndrome. Nevertheless, although thyroid dysfunction may also be observed in other genetic syndromes, such as Prader-Willi or Williams syndrome, the thyroid dysfunction in these syndromes is not the result of thyroid autoimmunity. Interestingly, there is emerging evidence supporting a possible link between autoimmunity and RASopathies. In this review article the incidence, as well as the clinical manifestation and accompanied pathologies of ATD in specific genetic syndromes will be presented and regular follow-up for the early identification of the disorder will be proposed.

Recombinant GH treatment in a case of Costello syndrome with a 5-year follow-up

Costello syndrome (CS) is a rare member of the group of neuro-cardio-facio-cutaneous diseases known as RASopathies. CS involves characteristic dysmorphic craniofacial features, cardiac defects, and increased cancer susceptibility, depending on the heterozygous activating germline mutations in HRAS. Polyhydramnios and high birth weight are the most common presentations in the perinatal and neonatal periods; while poor postnatal growth, short stature, and failure to thrive are significant issues in infancy. Possible mechanisms of short stature in CS include GH deficiency and feeding difficulties. Only a few reported cases of CS with GH deficiency exist in literature. Here, we describe the 5-yr follow-up of a CS patient with complete GH deficiency treated with recombinant human GH (rhGH) from the age of four years. No significant adverse events regarding progression of hypertrophic cardiomyopathy and tumor development were observed. She has been responsive to treatment with improved growth velocity and height standard deviation scores. She is still under continuous monitoring for concerns on the possible development of cardiac events and malignancies. This case indicated that rhGH therapy is effective for improving the height and growth velocity of CS patients with GH deficiency under close cardiac and oncological monitoring.