A case report of Noonan syndrome-like disorder with loose anagen hair 2 treated with recombinant human growth hormone.

Protein phosphatase 1 catalytic subunit beta (PPP1CB) is a disease-causing gene of Noonan-like syndrome, which acts via the RAS/MAPK pathway. To date, only 17 patients diagnosed with PPP1CB-related Noonan-like syndrome have been reported around the world, with few reports in Asia. Twelve reported patients are of short stature and only one patient was treated with growth hormone (GH); however, follow-up data is lacking. To the best of our knowledge, this is the first reported patient with complete recombinant human growth hormone (rhGH) treatment follow-up data; the patient has a de novo c.146C>G (p.Pro49Arg) mutation in the PPP1CB gene. The hair pattern of the patient (coarse, curly, slow growing, and fragile) combined with Noonan dysmorphic features, developmental delay, and congenital heart disease, are highly consistent with the typical features observed in Noonan syndrome-like disorder with loose anagen hair 2 (NSLH2). rhGH treatment, administered for 3 years and 8 months, promoted the patient's linear growth. Our findings expand the data regarding the treatment of short stature in patients with NSLH2 caused by PPP1CB mutation. Clinical manifestation, growth and development process, and rhGH therapy effect data will aid in future revision of the relevant diagnosis and treatment guidelines.

Improved growth velocity of a patient with Noonan-like syndrome with loose anagen hair (NS/LAH) without growth hormone deficiency by low-dose growth hormone therapy.

Noonan-like syndrome with loose anagen hair (NS/LAH; OMIM 607721) is caused by a heterozygous c.4A>G mutation in SHOC2. Most cases exhibit both growth hormone deficiency (GHD) and growth hormone insensitivity (GHI) and thus require a high dose of growth hormone (GH) therapy (e.g., 35-40 µg/kg/day). We report on a genetically diagnosed NS/LAH patient manifesting severe short stature (-3.85 SDs) with low serum level of IGF1, 30 ng/ml. The peak levels of GH stimulation tests were within the normal range, and GHI was not observed in the IGF1 generation test. However, with low-dose GH therapy (25 µg/kg/day) for two years, IGF1 level and height were remarkably improved (IGF1: 117 ng/ml, height SDs: -2.20 SDs). Further, catch-up of motor development and improvement of the proportion of extending limbs to trunk were observed (the Developmental Quotient score increased from 68 to 98 points, and the relative sitting height ratio decreased from 0.62 to 0.57). Our results suggest that endocrinological causes for short stature are variable in NS/LAH and that GH therapy should be considered as a possible treatment for delayed development in NS/LAH.

Minoxidil 5% solution for topical treatment of loose anagen hair syndrome.

A 2-year-old girl with a diagnosis of loose anagen hair syndrome was treated with a tapering regime of minoxidil 5% solution over 28 months, resulting in quick, significant clinical improvement with no adverse effects.

Coarctation of the aorta in Noonan-like syndrome with loose anagen hair.

Noonan-like syndrome with loose anagen hair (NS/LAH; OMIM 607721) due to a missense mutation c.4A>G in SHOC2 predicting p.Ser2Gly has been described recently. This condition is characterized by facial features similar to Noonan syndrome, reduced growth, cardiac defects, and typical abnormal hair. We report on a patient with molecularly confirmed NS/LAH with coarctation of the aorta. The girl was precipitously born at 37 weeks of gestation at home and required a 3-min resuscitation. Increased nuchal translucency and aortic coarctation with a small ventricular septal defect were described prenatally, hypertrophic cardiomyopathy was detected postnatally. The patient presented with facial dysmorphism typical of NS with redundant skin over the nape and on the back. Short stature, relative macrocephaly, failure-to-thrive together with dystrophic appearance, developmental delay mainly in motor milestones and very thin, sparse, slow-growing hair occurred a few weeks after birth. Endocrine evaluation revealed low IGF-1 levels and borderline growth hormone deficiency. Growth hormone therapy started at 16 months had a partial effect and prevented further growth deterioration. Coarctation of the aorta is not a typical heart defect among individuals with NS/LAH, therefore our observation extends the phenotypic spectrum of this disorder.

GH Therapy and first final height data in Noonan-like syndrome with loose anagen hair (Mazzanti syndrome).

Noonan-like syndrome with loose anagen hair (NS/LAH or Mazzanti Syndrome) is caused by a single missense mutation in SHOC2 promoting tN-myristoylation of the encoded protein. Cardinal features include facial features resembling NS, short stature often associated with proven growth hormone deficiency (GHD), typical ectodermal anomalies, and distinctive behavior. Overall, the clinical features are more severe than those generally observed in NS, even though the phenotype improves with age. We report on growth and pubertal trend in seven patients heterozygous for a mutated SHOC2 allele, treated with long-term GH-therapy, and final height (FH) in three of them. They were approximately -3 SDS below the Italian general population standards, they had very low IGF1 levels at baseline and GHD at pharmacological tests. All patients were treated with GH (0.035 mg/kg/day) for a mean period of 8.49 ± 5.72 years. After the 1st year of GH-therapy, IGF1 level and height velocity had increased. Three of 7 patients reached the FH (-2.34 ± 0.12 SDS) at 18.25 ± 0.73 years, after GH administration for 12.39 ± 2.12 years. Pubertal development was variable, showing a prolonged and delayed puberty or rapid pubertal progression that could impair the FH. Overall, our data in this small cohort suggest that NS/LAH patients benefit from long-term GH-therapy, although they do not show the characteristic catch-up growth of isolated GHD. While the observed growth and pubertal behavior is consistent with a dysfunction of the hypothalamic-pituitary-gonadal axis, the functional link between SHOC2 and the GH/IGF signaling pathways remains to be clarified.