Buccally Administered Intranasal Desmopressin Acetate for the Treatment of Neurogenic Diabetes Insipidus in Infancy

CONTEXT

The treatment of neurogenic diabetes insipidus (DI) in infancy is challenging and complicated by fluid overload and dehydration. Therapy with subcutaneous (SC), intranasal (IN), or oral tablet desmopressin acetate (1-desamino-8-D-arginine vasopressin [DDAVP]) remains difficult to titrate in infants.

OBJECTIVE

Assess the efficacy and safety of buccally administered IN DDAVP for the management of infants with neurogenic DI.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

Retrospective review of clinical and laboratory data of 15 infants (mean age, 4.5 mo) with neurogenic DI treated at a tertiary care center. Treatment was with diluted IN DDAVP formulation (10 mcg/mL) administered buccally via a tuberculin syringe to the buccal mucosa.

RESULTS

After initial DDAVP titration of 2-3 days, IN DDAVP doses ranged from 1 to 5 mcg twice daily given buccally. Mean serum sodium concentration at DI diagnosis was 159 ± 6.6 mmol/L (range, 151-178) and improved to 142 ± 3.5 mmol/L (range, 137-147) with the buccally administered IN DDAVP. Normal sodium concentrations were established without major fluctuations. Serum sodium was then maintained in the outpatient setting at a mean of 145.7 ± 4.8 mmol/L (mean duration of follow-up, 11 mo).

CONCLUSIONS

Buccally administered IN formulation of DDAVP provides a practical and safe treatment alternative for neurogenic DI in infancy. Our approach avoided severe hypo- and hypernatremia during DDAVP titration and ongoing outpatient management of DI. The possibility for smaller dosage increments and ease of administration make IN DDAVP administered buccally preferable over other DDAVP treatment options in infants.

Transient Intraoperative Central Diabetes Insipidus in Moyamoya Patients Undergoing Revascularization Surgery: A Mere Coincidence?

We present 2 patients with Moyamoya disease undergoing revascularization surgery who developed transient intraoperative central diabetes insipidus with spontaneous resolution in the immediate postoperative period. We speculate that patients with Moyamoya disease may be predisposed to a transient acute-on-chronic insult to the arginine vasopressin-producing portion of their hypothalamus mediated by anesthetic agents. We describe our management, discuss pertinent literature, and offer possible mechanisms of this transient insult. We hope to improve patient safety by raising awareness of this potentially catastrophic complication.

Autoimmune lymphocytic hypophysitis in association with autoimmune eye disease and sequential treatment with infliximab and rituximab

INTRODUCTION

Autoimmune lymphocytic hypophysitis associates predominantly with other autoimmune endocrinopathies and is most commonly treated with glucocorticoids and/or decompressive pituitary surgery. Here we report a new association and treatment modality for lymphocytic hypophysitis.

METHODS

A 52-year-old woman presented with scleritis, uveitis, facial palsy, and central diabetes insipidus, accompanied by thickened pituitary stalk and enlarged pituitary on cranial MRI. Neurosarcoidosis was suspected and treatment with glucocorticoids and methotrexate initiated. Since symptoms persisted, infliximab (a monoclonal antibody that antagonizes tumor necrosis factor alpha) was added to her regimen. The patient initially improved but after 6 months developed recurrent pituitary enlargement, bilateral optic neuritis, and panhypopituitarism. To ascertain the nature of the pituitary lesion, she underwent transsphenoidal biopsy, which revealed lymphocytic hypophysitis with numerous CD20 positive B lymphocytes. The pathological finding suggested to us that administration of rituximab (a monoclonal antibody that lyzes B cells expressing CD20) could be useful. Following two courses of rituximab, the pituitary mass resolved and the corticotroph axis partially recovered. The patient has remained in remission during 3 years of follow up.

CONCLUSION

This is the first report of hypophysitis occurring with the triad of scleritis, uveitis, and optic neuritis, as well as the first immunotherapy based on the sequential use of infliximab and rituximab.

Management of diabetes insipidus and adipsia in the child

Central diabetes insipidus (CDI) is a complex and heterogeneous clinical syndrome affecting the hypothalamic-neurohypophyseal network and water balance. A recent national surveillance in Denmark showed a prevalence rate of twenty-three CDI patients per 100,000 inhabitants in five years. The differential diagnosis between several presenting conditions with polyuria and polydipsia is puzzling, and the etiological diagnosis of CDI remains a challenge before the identification of an underlying cause. For clinical practice, a timely diagnosis for initiating specific treatment in order to avoid central nervous system damage, additional pituitary defects and the risk of dissemination of germ cell tumor is advisable. Proper etiological diagnosis can be achieved via a series of steps that start with careful clinical observation of several signs and endocrine symptoms and then progress to more sophisticated imaging tools. This review summarizes the best practice and approach for the diagnosis and treatment of patients with CDI.

Pregnancy may favour the development of severe autoimmune central diabetes insipidus in women with vasopressin cell antibodies: description of two cases

Recently, an increased incidence of central diabetes insipidus (CDI) in pregnancy, and less frequently in the post partum period, has been reported, most probably favoured by some conditions occurring in pregnancy. This study was aimed at investigating the influence of pregnancy on a pre-existing potential/subclinical hypothalamic autoimmunity. We studied the longitudinal behaviour of arginine-vasopressin cell antibodies (AVPcAbs) and post-pituitary function in two young women with a positive history of autoimmune disease and presence of AVPcAbs, but without clinical CDI, and who became pregnant 5 and 7 months after our first observation. The behaviour of post-pituitary function and AVPcAbs (by immunofluorescence) was evaluated at baseline, during pregnancy and for 2 years after delivery. AVPcAbs, present at low/middle titres at baseline in both patients, showed a titre increase during pregnancy in one patient and after delivery in the other patient, with development of clinically overt CDI. Therapy with 1-deamino-8-d-arginine vasopressin (DDAVP) caused a prompt clinical remission. After a first unsuccessful attempt of withdrawal, the therapy was definitively stopped at the 6th and the 7th month of post partum period respectively, when AVPcAbs disappeared, accompanied by post-pituitary function recovery, persisting until the end of the follow-up. The determination of AVPcAbs is advisable in patients with autoimmune diseases planning their pregnancy, because they could be considered good predictive markers of gestational or post partum autoimmune CDI. The monitoring of AVPcAb titres and post-pituitary function during pregnancy in these patients may allow for an early diagnosis and an early replacement therapy, which could induce the disappearance of these antibodies with consequent complete remission of CDI.

Central diabetes insipidus: alert for dehydration in very low birth weight infants during the neonatal period. A case report

CONTEXT

Central diabetes insipidus (CDI) is a rare cause of hypernatremia during the neonatal period. The diagnosis is particularly difficult in very low birth weight (VLBW) newborns.

CASE REPORT

We report on a preterm newborn who presented CDI soon after birth. On the third day of life, signs of dehydration were present despite normal fluid supply. The diuresis rate was 4.4 ml/kg/h. Although the fluid supply was then increased, the dehydration continued, with hypernatremia, normal glycemia, diuresis of 7.4 ml/kg/h and urine density of 1005 mOsmol/l. Thus, a diagnostic hypothesis of diabetes insipidus was raised. A test with a nasal vasopressin analogue (dDAVP) was performed and CDI was confirmed. Reduction of the fluid supply became possible through appropriate treatment.

CONCLUSION

The diagnosis of CDI is rarely made during the neonatal period, especially in VLBW newborns, because of the difficulty in detecting elevated diuresis. Persistent hypernatremia, usually accompanied by hyperthermia despite abundant fluid supply, weight loss and low urine osmolality are important signs of alert.

Comparison of incidence of hyponatremia between intranasal and oral desmopressin in patients with central diabetes insipidus

Central diabetes insipidus (CDI), which is characterized by polyuria and polydipsia, is caused by a deficiency of the antidiuretic hormone arginine vasopressin (AVP). While CDI is treated with desmopressin, an analogue of AVP, the intranasal formulation is inconvenient and CDI patients reportedly prefer the oral formulation to the intranasal one. In Japan, intranasal desmopressin had been the only formulation for the treatment of CDI until 2012, when the desmopressin orally disintegrating tablet (ODT) was approved for treatment. In this study we analyzed 26 patients with CDI in whom intranasal desmopressin was switched to desmopressin ODT. The mean daily dose of intranasal desmopressin was 10 ± 8 μg/day, and that of desmopressin ODT was 142 ± 59 μg/day. The mean serum sodium levels were 140 ± 5 mmol/L and 140 ± 3 mmol/L with intranasal desmopressin and desmopressin ODT, respectively, and there were no significant differences between these values. The frequency of hyponatremia (<135 mmol/L) with intranasal desmopressin was 11.7% and that with desmopressin ODT was 7.6%, while the frequency of hyponatremia (<130 mmol/L) with intranasal desmopressin was 4.2% and that with desmopressin ODT was 1.3%. Statistical analyses revealed that incidence of hyponatremia was significantly decreased after the switch to desmopressin ODT. Thus, it is suggested that water balance is better controlled with desmopressin ODT than with intranasal desmopressin in patients with CDI.

Idiopathic central diabetes insipidus presenting in a very low birth weight infant successfully managed with lyophilized sublingual desmopressin

Neonatal central diabetes insipidus (DI) is an extremely rare disorder that can cause severe morbidity and mortality. We have reported a very low birth weight infant with idiopathic central DI presenting in the first month of life who was successfully treated with sublingual desmopressin therapy. In this report, we emphasize that central DI should be kept in mind in an infant with unexplained hypernatremia and polyuria. Timely diagnosis and treatment with lyophilized desmopressin may prevent severe morbidity and mortality.

Management of central diabetes insipidus with oral desmopressin lyophilisate in infants

AIM

To assess the efficiency of oral desmopressin lyophilisate (ODL) in neonatal central diabetes insipidus (CDI).

METHODS

The characteristics of four newborns with CDI treated with ODL were evaluated.

RESULTS

Four newborns with polyuria and hypernatremia were included [male, 2 (50%); mean postnatal age, 19±17 days]. At the time of hypernatremia, the mean serum and urine osmolality values were 310±16 and 179±48 mOsm/kg, respectively. Antidiuretic hormone levels were undetectable (<0.5 pmol/L) in all cases. Magnetic resonance imaging revealed anatomical malformations in all cases. ODL (60 μg/tablet) dissolved in water (3-5 mL) was initiated with a dose of 5 μg/kg/day in two equal doses, together with limitation of water intake to avoid hyponatremia. Serum sodium levels returned to normal in a mean duration of 58±9.9 h with a mean decline rate of 0.37±0.1 mEq/L/h after desmopressin administration. Rehospitalization was required for one of the infants because of hypernatremia due to non-compliance. No episode of hyponatremia was encountered. Weight gain and growth of the infants were normal during the mean follow-up duration of 8.5±1 months.

CONCLUSIONS

ODL appears to be practical and safe in the treatment of CDI during the first year of life.

National Surveillance of Central Diabetes Insipidus (CDI) in Denmark: results from 5 years registration of 9309 prescriptions of desmopressin to 1285 CDI patients

CONTEXT

Epidemiological data for central diabetes insipidus (CDI) are sparse.

OBJECTIVE

The purpose of this study was to provide accurate epidemiological data on CDI on a national level.

DESIGN AND SETTING

This was a drug utilization and patient registry study during a 5-year period from 2007 to 2011.

METHODS

We used the Danish National Prescription Registry data linked with the Danish National Patient Registry to study the epidemiology of CDI using waiting time distribution and other pharmacoepidemiological methods.

PATIENTS

A total of 1285 patients with CDI were recorded in the observation period and given 9309 prescriptions for desmopressin in the nasal formulation, orodispersible tablet, or conventional tablet.

RESULTS

The period prevalence rate of CDI in Denmark over the 5-year period investigated was 23 CDI patients per 100 000 inhabitants, with a higher prevalence in children and older adults (>80 years of age). The 1-year period prevalence rate of CDI decreased in Denmark over the 5 years from approximately 10 to 7 CDI patients per 100 000 inhabitants. The yearly incidence rate of new cases of CDI was found to be 3 to 4 patients per 100 000. The incidence of (presumable) congenital CDI was found to be 2 infants per 100 000 infants. Half of the patients with CDI prescribed as oral treatment were provided dosing instructions to only administer the drug before bedtime, and one third of the CDI patients either had no specific instructions or were instructed to use the drug as needed. Hospital admissions due to severe hyponatremia occurred in 0.9% of patients over a 5-year period, predominantly in females with an incidence ratio of women to men of 1.8:1.

CONCLUSION

Half of the cases of CDI are acquired later in life. At least half of the patients with CDI are instructed to prevent nocturnal polyuria, but it is not clear whether their CDI remains uncontrolled during the daytime or, alternatively, whether they use desmopressin only as needed. Female patients with CDI had approximately twice the number of hospital admissions due to severe hyponatremia than male patients with CDI.

Desmopressin orally disintegrating tablet in Japanese patients with central diabetes insipidus: a retrospective study of switching from intranasal desmopressin

Central diabetes insipidus (CDI) is a rare disease characterized by polyuria and polydipsia. Patients with CDI have been successfully treated with desmopressin administered either by intranasal instillation or oral tablets. Recently, a desmopressin orally disintegrating tablet (ODT) was approved as the first oral desmopressin tablet for CDI treatment in Japan. We conducted a retrospective single-center study of 15 Japanese CDI patients treated with desmopressin ODT therapy, which aimed to evaluate the efficacy and safety of switching to desmopressin ODT and to analyze the clinical factors that affect the desmopressin ODT dose in Japanese patients. The daily mean dose of desmopressin ODT was 104 ± 46.30 μg and the mean ratio of oral to nasal desmopressin dose was 17.0 ± 7.6, both of which are considerably smaller than those of previous dose-titration study. Moreover, the nasal spray group needed significantly smaller ratios of nasal to oral desmopressin than the nasal drop group (11.7 ± 6.5 vs 21.0 ± 5.5, p = 0.02). The ratio of oral to nasal desmopressin dose had a significant inverse correlation with the required nasal desmopressin dose. Multiple regression analysis demonstrated the ratios of nasal to oral desmopressin dose depended on intranasal formulations. In conclusion, desmopressin ODT was safe and effective in the treatment of Japanese adult CDI patients. When switching to ODT, we should care about the possibility that patients require smaller ODT doses than what was initially expected based on previously published data and also nasal formulations in terms of their differences of expected switching ratio.

Clinical review: Treatment of neurohypophyseal diabetes insipidus

CONTEXT

In recent years, there have been several improvements in the treatment of neurohypophyseal diabetes insipidus (DI). They include new formulations of the vasopressin analog, desmopressin; a better understanding of the effect of fluid intake on dosing; and more information about treatments of infants, children, and pregnant women who present special challenges. This review aims to summarize past and current information relative to the safety and efficacy of treatments for the types of DI caused by a primary deficiency of vasopressin.

EVIDENCE ACQUISITION

The review is based on publications identified primarily by a PubMed search of the international literature without limitations of date.

EVIDENCE SYNTHESIS

In acute settings where fluid intake is determined by factors other than thirst, desmopressin should be given iv in doses that have a short duration of action and can be adjusted quickly in accordance with changes in hydration as indicated by plasma sodium. In ambulatory patients, the oral formulations (tablet or melt) are preferred for their convenience. If fluid intake is regulated normally by the thirst mechanism, the tablets or melt can be taken safely 1 to 3 times a day in doses sufficient to completely eliminate the polyuria. However, if fluid intake consistently exceeds replacement needs as evidenced by the development of hyponatremia, the dose should be reduced to allow higher than normal rates of urine output or intermittent breakthrough diuresis. This regimen is often indicated in infants or children because their rate of fluid intake tends to be greater than in adults. In all cases, the appropriate dose should be determined by titration, owing to considerable interindividual differences in bioavailability and antidiuretic effect.

CONCLUSIONS

Desmopressin can provide effective and safe therapy for all patients with neurohypophyseal or gestational DI if given in doses and by a route that takes into account the determinants of fluid intake.

Severe water intoxication secondary to the concomitant intake of non-steroidal anti-inflammatory drugs and desmopressin: a case report and review of the literature

Most of the clinical data on the safety profile of desmopressin (DDAVP), which is an effective treatment for both polyuric conditions and bleeding disorders, originate from studies on the tailoring of drug treatment, whereas few reports exist describing severe side effects secondary to drug-drug interaction. We herein describe a case of severe hyponatremia complicated by seizure and coma due to the intake of non-steroidal anti-inflammatory drugs (NSAIDs) in a patient on DDAVP replacement therapy for central diabetes insipidus (DI). A 50-yr-old Caucasian man, with congenital central DI, developed an episode of generalized tonic-clonic seizure, resulting in coma immediately after being admitted to the Emergency Unit for weakness and emesis. Based on his medical history and clinical findings, water intoxication secondary to ketoprofen intake (200 mg/day for the last 3 days) concomitant with DDAVP replacement therapy (Minirin(®) 60 mcg 4 tablets a day) was hypothesized as being the cause of the severe euvolemic hypotonic hyponatremia (natremia 113 mEq/l, plasma osmolality 238 mOsm/Kg). After standard emergency procedures, appropriate gradual restoration of serum sodium levels to the normal range was achieved in 72 hours. Hydratation was maintained according to water excretion and desmopressin therapy was re-introduced. We discuss this case report in the context of the published literature. The present report first highlights the potentially life-threatening side effects associated with over-the-counter NSAIDs during DDAVP replacement therapy for central DI. Risks and benefits of co-treatment should be carefully considered and therapeutic alternatives to NSAIDs should be recommended to patients with central DI in order to improve DDAVP safety.

Efficacy and safety of desmopressin orally disintegrating tablet in patients with central diabetes insipidus: results of a multicenter open-label dose-titration study

Central diabetes insipidus (CDI) is associated with arginine vasopressin (AVP) deficiency with resultant polyuria and polydipsia. Intranasal desmopressin provides physiological replacement but oral formulations are preferred for their ease of administration. This study aimed to demonstrate the efficacy and safety of desmopressin orally disintegrating tablet (ODT) in the treatment of Japanese patients with CDI, and confirm that antidiuresis is maintained on switching from intranasal desmopressin to desmopressin ODT. A total of 20 patients aged 6-75 years with CDI were included in this 4-week multicenter, open-label study. Following observation, patients switched from intranasal desmopressin to desmopressin ODT with titration to optimal dose over ≤5 days at the study site. Following three consecutive doses with stable patient fluid balance, patients were discharged with visits at Weeks 2 and 4. Following titration from intranasal desmopressin to ODT, the mean 24-hour urine volume was unchanged, indicating similar antidiuresis with both formulations. The proportion of patients with endpoint measurements (urine osmolality, 24-hour urine volume, hourly diuresis rate and urine-specific gravity) within normal range at Days 1-2 (intranasal desmopressin) and Week 4 (desmopressin ODT) was similar. The mean daily dose ratio of intranasal desmopressin to desmopressin ODT (Week 4) was 1:24 but a wide range was observed across individuals to maintain adequate antidiuretic effect. Hyponatraemia was generally mild and managed by dose titration. Desmopressin ODT achieved sufficient antidiuretic control compared to intranasal therapy and was well tolerated over long-term treatment. The wide range of intranasal:ODT dose ratios underline the importance of individual titration.

[Central diabetes insipidus: diagnosis and management]

Central diabetes insipidus (CDI) is caused by deficient secretion of antidiuretic hormone (ADH) due to different conditions that can affect the hypothalamic neurons. It results in an inability to retain normal quantities of free water, which leads to polyuria, including at night, and polydipsia. In adults, it is mostly due to the "idiopathic" form or present after pituitary surgery or a traumatic brain injury. In rare cases, an underlying systemic disease is found. The diagnosis of CDI is based on the water deprivation test. Pituitary MRI and specific clinical and biological work-up are recommended to precise etiology. Treatment of choice is desmopressin, a synthetic analogue of the endogenous ADH hormone. A multidisciplinary team generally provides management and monitoring of CDI.

The hypothalamic-neurohypophyseal system: current and future treatment of vasopressin and oxytocyn related disorders

The hypothalamus and posterior pituitary form a complex neurohumoral system playing a key role in maintaining body fluid homeostasis and reproductive function. We review the pathophysiology mechanisms of posterior pituitary hormones and their implications, beyond water balance and delivery, in social functioning, pair bonding and affiliative behavior. Actual and future treatments for neurohypophysis related disorders are also discussed, particularly focusing on the development of new therapeutic compounds and patents.

A case of transient central diabetes insipidus after aorto-coronary bypass operation

Diabetes insipidus (DI) is characterized by excessive urination and thirst. This disease results from inadequate output of antidiuretic hormone (ADH) from the pituitary gland or the absence of the normal response to ADH in the kidney. We present a case of transient central DI in a patient who underwent a cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG). A 44-yr-old male underwent a CABG operation. An hour after the operation, the patient developed polyuria and was diagnosed with central DI. The patient responded to desmopressin and completely recovered five days after surgery. It is probable that transient cerebral ischemia resulted in the dysfunction of osmotic receptors in the hypothalamus or hypothalamus-pituitary axis during CPB. It is also possible that cardiac standstill altered the left atrial non-osmotic receptor function and suppressed ADH release. Therefore, we suggest that central DI is a possible cause of polyuria after CPB.

Profound hypernatremia due to central diabetes insipidus

Diabetes insipidus is a rare endocrine disorder in paediatric patients. Polyuria is a cardinal manifestation that is extremely difficult to recognize in diapered infants. Careful urine quantification is the key to diagnosis in appropriate clinical setting. We report a case of a 4 months old infant presenting with an acute life threatening event following an episode of vomiting and decreased oral intake. She had profound hypernatremia which persisted after stabilization. Polyuria unrecognized by the mother was revealed by 24-hour urine output measurement. A diagnosis of diabetes insipidus was made after appropriate laboratory investigations including serum and urine osmolality. The central nature of the disease was confirmed by neuroimaging which showed holoprosencephaly.

Desmopressin-induced posterior reversible encephalopathy syndrome

We herein report the case of a patient who presented with an acute decrease of visual acuity, hypertension, focal seizures and transient mental dysfunction while undergoing desmopressin treatment. Neuroimaging revealed bilateral occipital-parietal lesions that presented with vasogenic edema. After controlling the hypertension and discontinuing the desmopressin treatment, the patient's condition improved. A follow-up imaging examination performed six months later showed complete resolution of the lesions. It is important to recognize posterior reversible encephalopathy syndrome (PRES) as a rare and serious complication of desmopressin administration. Both the blood pressure and water electrolyte balance should be carefully monitored in patients receiving desmopressin therapy.

Desmopressin duration of antidiuretic action in patients with central diabetes insipidus

The key question answered by this study is whether it is possible to deliver a pharmacokinetic and pharmacodynamic duration of antidiuretic action long enough to ensure adequate antidiuresis with two daily administrations of desmopressin in patients with central diabetes insipidus (CDI). We studied the efficacy and safety of desmopressin i.v. in 13 CDI patients using two 3-way crossover designs, in the doses 30, 60, 125 ng, and 125, 250 and 500 ng. Duration of action, minimum output rate, max osmolality and average osmolality during action (AUC osmolality) were measured every 30 min for the first 2 h during the infusion, and then every hour or every second hour until the urine output rate was greater than 2 ml/kg/30 min. The duration of antidiuretic action was 4, 8 and 11 h, respectively, for 125, 250, and 500 ng, increasing from 250 to 500 ng but for the remaining secondary dynamic efficacy parameters no difference could be detected based on descriptive statistics between the doses 250 and 500 ng, indicating that the upper plateau region of the dose-response curve had been reached. All treatment emergent adverse events were classified as unrelated or unlikely related to trial medication. No serious adverse events occurred. Data on duration of action indicates that it is possible to achieve antidiuretic control with 500 ng i.v. corresponding to 160 μg orodispersible tablets twice daily in CDI patients. Today, the Minirin Melt label recommends the majority of CDI patients a dose of 60 to 120 μg t.i.d.

Familial neurohypophyseal diabetes insipidus due to a novel mutation in the arginine vasopressin-neurophysin II gene

BACKGROUND

Familial neurohypophyseal (central) diabetes insipidus (DI) is caused by mutations in the arginine vasopressin-neurophysin II (AVP-NPII) gene. The majority of cases is inherited in an autosomal dominant way. In this study, we present the clinical features of a mother and her son with autosomal dominant neurohypophyseal DI caused by a novel mutation.

CASE

A thirty-four-year-old woman and her three-year-old son were evaluated because of polyuria and polydipsia since the age of 1.5 years onwards. Both patients were subjected to a water deprivation test confirming the diagnosis of central DI. Magnetic resonance imaging of the brain of the mother showed a hypothalamus without apparent abnormalities and a relatively small neurohypophysis without a hyperintense signal. Mutation analysis showed a c.322G>T (p.?/p.Glu108X) in Exon 2 of the AVP-NPII gene in both mother and son.

DISCUSSION

This study reports neurohypophyseal DI in a mother and her son due to a novel mutation in Exon 2 of the AVP-NPII gene. Clinical and pathophysiological aspects of this disease are shortly reviewed and discussed.