Co-occurrence of mutations in KIF7 and KIAA0556 in Joubert syndrome with ocular coloboma, pituitary malformation and growth hormone deficiency: a case report and literature review.

BACKGROUND: Joubert syndrome is a recessive neurodevelopmental disorder characterized by clinical and genetic heterogeneity. Clinical hallmarks include hypotonia, ataxia, facial dysmorphism, abnormal eye movement, irregular breathing pattern cognitive impairment and, the molar tooth sign is the pathognomonic midbrain-hindbrain malformation on magnetic resonance imaging. The disorder is predominantly caused by biallelic mutations in more than 30 genes encoding proteins with a pivotal role in morphology and function of the primary cilium. Oligogenic inheritance or occurrence of genetic modifiers has been suggested to contribute to the variability of the clinical phenotype. We report on a family with peculiar clinical spectrum Joubert syndrome molecularly and clinically dissecting a complex phenotype, in which hypogonadism, pituitary malformation and growth hormone deficiency occur as major features. CASE PRESENTATION: A 7 year-old male was enrolled in a dedicated "Undiagnosed Patients Program" for a peculiar form of Joubert syndrome complicated by iris and retinochoroidal coloboma, hypogonadism pituitary malformation, and growth hormone deficiency. The molecular basis of the complex phenotype was investigated by whole exome sequencing. The concomitant occurrence of homozygosity for mutations in KIF7 and KIAA0556 was identified, and the assessment of major clinical features associated with mutations in these two genes provided evidence that these two independent events represent the cause underlying the complexity of the present clinical phenotype. CONCLUSION: Beside the clinical variability of Joubert syndrome, co-occurrence of mutations in ciliopathy-associated genes may contribute to increase the clinical complexity of the trait.

Congenital primary adrenal insufficiency and selective aldosterone defects presenting as salt-wasting in infancy: a single center 10-year experience.

BACKGROUND: Salt-wasting represents a relatively common cause of emergency admission in infants and may result in life-threatening complications. Neonatal kidneys show low glomerular filtration rate and immaturity of the distal nephron leading to reduced ability to concentrate urine. METHODS: A retrospective chart review was conducted for infants hospitalized in a single Institution from 1(st) January 2006 to 31(st) December 2015. The selection criterion was represented by the referral to the Endocrinology Unit for hyponatremia (serum sodium <130 mEq/L) of suspected endocrine origin at admission. RESULTS: Fifty-one infants were identified. In nine infants (17.6 %) hyponatremia was related to unrecognized chronic gastrointestinal or renal salt losses or reduced sodium intake. In 10 infants (19.6 %) hyponatremia was related to central nervous system diseases. In 19 patients (37.3 %) the final diagnosis was congenital adrenal hyperplasia (CAH). CAH was related to 21-hydroxylase deficiency in 18 patients, and to 3ß-Hydroxysteroid dehydrogenase (3ßHSD) deficiency in one patient. Thirteen patients (25.5 %) were affected by different non-CAH salt-wasting forms of adrenal origin. Four familial cases of X-linked adrenal hypoplasia congenita due to NROB1 gene mutation were identified. Two unrelated girls showed aldosterone synthase deficiency due to mutation of the CYP11B2 gene. Two unrelated infants were affected by familial glucocorticoid deficiency due to MC2R gene mutations. One girl showed pseudohypoaldosteronism related to mutations of the SCNN1G gene encoding for the epithelial sodium channel. Transient pseudohypoaldosteronism was identified in two patients with renal malformations. In two infants the genetic aetiology was not identified. CONCLUSIONS: Emergency management of infants presenting with salt wasting requires correction of water losses and treatment of electrolyte imbalances. Nevertheless, the differential diagnosis may be difficult in emergency settings, and sometimes hospitalized infants presenting with salt-wasting are immediately started on steroid therapy to avoid life-threatening complications, before the correct diagnosis is reached. Physicians involved in the management of infants with salt-wasting of suspected hormonal origin should remember that, whenever practicable, a blood sample for the essential hormonal investigations should be collected before starting steroid therapy, to guide the subsequent diagnostic procedures and in particular to address the analysis of candidate genes.

Partially reversible hypopituitarism in an adolescent with a rathke cleft cyst.

Rathke cleft cysts are remnants of the Rathke pouch. Most of them are asymptomatic, but sometimes they can grow enough to cause compression of structures within and/or close to the sella, thus eliciting symptoms such as visual disturbance, pituitary defects, and headache. Asymptomatic cysts can safely be followed up with serial imaging, while the standard treatment for symptomatic lesions is surgical removal. We describe a 14-yr-old boy, admitted for anorexia, fatigue, weight loss, recurrent headache and vomiting. Magnetic resonance imaging showed an intra- and suprasellar cystic lesion, which was surgically removed. Histology was consistent with Rathke's cleft cyst. Diabetes insipidus and multiple anterior pituitary defects (GH, ACTH and TSH) were found preoperatively, and substitutive therapy was started. No additional hormonal defect appeared after surgery. After 4 yr of follow up, pituitary function was retested, and there were no confirmed GH or ACTH defects, allowing a partial withdrawal of replacement therapy. Our report confirms that pituitary defects, in patients with a Rathke cleft cyst, may recover even year after surgery. Thus, retesting of pituitary axes is indicated during long-term follow up.

Clinical features suggestive of non-classical 21-hydroxylase deficiency in children presenting with precocious pubarche.

Precocious pubarche (PP) is defined as the onset of pubic hair at 8 years of age in girls and at 9 years of age in boys. PP is idiopathic (IPP) in most children, but it is the earliest manifestation of non-classical congenital adrenal hyperplasia owing to steroid 21-hydroxylase deficiency (NC21OHD) in 5%-20% of cases. 17-Hydroxyprogesterone (17OHP) levels after ACTH stimulation test are used to distinguish the two forms. We studied clinical indicators of NC21OHD in 289 PP children: 14 (4.8%) showed post-ACTH 17OHP levels >30 nmol/L and NC21OHD due to CYP21A2 gene mutations was confirmed. NC21OHD children were younger (p: 0.006) and thinner (p: 0.003) than IPP children. Height standard deviation score (SDS) was not different (p: 0.97). NC21OHD girls showed more advanced bone age than IPP girls (p<0.001). Earlier PP onset and bone age advance suggest NC21OHD, which requires confirmation by an ACTH stimulation test. Later, PP appearance in overweight children suggests IPP and could merit only clinical monitoring.