Diagnosis and management of neonatal diabetes mellitus: A survey of physicians' perceptions and practices in ASPED countries

AIM

To ascertain the awareness and practice of neonatal diabetes mellitus (NDM) among paediatricians in Arab countries.

METHODS

An online questionnaire was distributed to physicians associated with the Arab Society for Paediatric Endocrinology and Diabetes (ASPED).

RESULTS

We received 126 replies, from 16 countries. All except one classified the survey's case scenario as NDM and 94% agreed that NDM patients should have detailed assessment to identify extra-pancreatic features. Although 92% felt that genetic testing is necessary, only 72% requesting them routinely and 32% unaware of the availability of free genetic testing. Insulin is considered the initial therapy for 93% and 80% diluted insulin to deliver accurate doses. Basal-bolus regimen was preferred by 36% and similar percentage used insulin pump. The remaining 28% favour long acting insulin alone. Oral sulfonylureas would be tried empirically by 34% and 69% would do so if genetic testing is unavailable. Whilst 70% have no local NDM management guidelines, 41% are unaware of any international guidelines.

CONCLUSIONS

The ASPED surveyed clinicians have good awareness of NDM diagnosis with marked variation in their practice raising the need to establish management guideline for the condition. The survey highlights areas to focus on in developing consensus and educational activities.

Pharmacogenomics in diabetes: outcomes of thiamine therapy in TRMA syndrome

AIMS/HYPOTHESIS

Diabetes is one of the cardinal features of thiamine-responsive megaloblastic anaemia (TRMA) syndrome. Current knowledge of this rare monogenic diabetes subtype is limited. We investigated the genotype, phenotype and response to thiamine (vitamin B1) in a cohort of individuals with TRMA-related diabetes.

METHODS

We studied 32 individuals with biallelic SLC19A2 mutations identified by Sanger or next generation sequencing. Clinical details were collected through a follow-up questionnaire.

RESULTS

We identified 24 different mutations, of which nine are novel. The onset of the first TRMA symptom ranged from birth to 4 years (median 6 months [interquartile range, IQR 3-24]) and median age at diabetes onset was 10 months (IQR 5-27). At presentation, three individuals had isolated diabetes and 12 had asymptomatic hyperglycaemia. Follow-up data was available for 15 individuals treated with thiamine for a median 4.7 years (IQR 3-10). Four patients were able to stop insulin and seven achieved better glycaemic control on lower insulin doses. These 11 patients were significantly younger at diabetes diagnosis (p = 0.042), at genetic testing (p = 0.01) and when starting thiamine (p = 0.007) compared with the rest of the cohort. All patients treated with thiamine became transfusion-independent and adolescents achieved normal puberty. There were no additional benefits of thiamine doses >150 mg/day and no reported side effects up to 300 mg/day.

CONCLUSIONS/INTERPRETATION

In TRMA syndrome, diabetes can be asymptomatic and present before the appearance of other features. Prompt recognition is essential as early treatment with thiamine can result in improved glycaemic control, with some individuals becoming insulin-independent.

DATA AVAILABILITY

SLC19A2 mutation details have been deposited in the Decipher database ( https://decipher.sanger.ac.uk/ ).

The spectrum of congenital heart diseases in down syndrome. A retrospective study from Northwest Saudi Arabia

Objectives:

To to define the frequency and patterns of congenital heart disease (CHD) among children with Down syndrome (DS) in Northwest Saudi Arabia.

Methods:

We included children with confirmed DS referred to the regional pediatric cardiology unit in Madinah Maternity and Children Hospital between January 2008 and December 2013. Children were identified from the unit’s data-base and the charts were reviewed retrospectively. We excluded term and preterm children with patent ducts arteriosus (PDA) and persistent foramen oval spontaneously resolved during the first 4 weeks of life.

Results:

A total of 302 children with DS were identified (50.3% male). Of these, 177 (58.6%) had CHD. Atrioventricular septal defect (AVSD) was the most frequent lesion identified in 72/177 (40.7%) followed by mixed left to right shunt defects (14.7%) and secundum atrial septal defect (ASD) (11.8%). Ventricular septal defect was detected in 10.7% and 8.5% had PDA beyond the neonatal period. There was no gender difference in the frequency of CHD (p=0.9) and the presence of CHD was not related to the genetic cause of DS (p=0.9).

Conclusion:

The frequency of CHD in our DS cohort is comparable with Europe, Asia, and other KSA regions. However its pattern appears to be different from some areas in KSA.

Homozygous Resistance to Thyroid Hormone β: Can Combined Antithyroid Drug and Triiodothyroacetic Acid Treatment Prevent Cardiac Failure?

Resistance to thyroid hormone β (RTHβ) due to homozygous THRB defects is exceptionally rare, with only five kindreds reported worldwide. Cardiac dysfunction, which can be life-threatening, is recognized in the disorder. Here we describe the clinical, metabolic, ophthalmic, and cardiac findings in a 9-year-old boy harboring a biallelic THRB mutation (R243Q), along with biochemical, physiologic, and cardiac responses to carbimazole and triiodothyroacetic acid (TRIAC) therapy. The patient exhibits recognized features (goiter, nonsuppressed thyroid-stimulating hormone levels, upper respiratory tract infections, hyperactivity, low body mass index) of heterozygous RTHβ, with additional characteristics (dysmorphic facies, winging of scapulae) and more markedly elevated thyroid hormone levels, associated with the homozygous form of the disorder. Notably, an older sibling with similar clinical features and probable homozygous RTHβ had died of cardiac failure at age 13 years. Features of early dilated cardiomyopathy in our patient prompted combination treatment with carbimazole and TRIAC. Careful titration of therapy limited elevation in TSH levels and associated increase in thyroid volume. Subsequently, sustained reduction in thyroid hormones with normal TSH levels was reflected in lower basal metabolic rate, gain of lean body mass, and improved growth and cardiac function. A combination of antithyroid drug and TRIAC therapy may prevent thyrotoxic cardiomyopathy and its decompensation in homozygous or even heterozygous RTHβ in which life-threatening hyperthyroid features predominate.

Comprehensive Screening of Eight Known Causative Genes in Congenital Hypothyroidism With Gland-in-Situ

CONTEXT

Lower TSH screening cutoffs have doubled the ascertainment of congenital hypothyroidism (CH), particularly cases with a eutopically located gland-in-situ (GIS). Although mutations in known dyshormonogenesis genes or TSHR underlie some cases of CH with GIS, systematic screening of these eight genes has not previously been undertaken.

OBJECTIVE

Our objective was to evaluate the contribution and molecular spectrum of mutations in eight known causative genes (TG, TPO, DUOX2, DUOXA2, SLC5A5, SLC26A4, IYD, and TSHR) in CH cases with GIS. Patients, Design, and Setting: We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silico.

PATIENTS, DESIGN, AND SETTING

We screened 49 CH cases with GIS from 34 ethnically diverse families, using next-generation sequencing. Pathogenicity of novel mutations was assessed in silico.

RESULTS

Twenty-nine cases harbored likely disease-causing mutations. Monogenic defects (19 cases) most commonly involved TG (12), TPO (four), DUOX2 (two), and TSHR (one). Ten cases harbored triallelic (digenic) mutations: TG and TPO (one); SLC26A4 and TPO (three), and DUOX2 and TG (six cases). Novel variants overall included 15 TG, six TPO, and three DUOX2 mutations. Genetic basis was not ascertained in 20 patients, including 14 familial cases.

CONCLUSIONS

The etiology of CH with GIS remains elusive, with only 59% attributable to mutations in TSHR or known dyshormonogenesis-associated genes in a cohort enriched for familial cases. Biallelic TG or TPO mutations most commonly underlie severe CH. Triallelic defects are frequent, mandating future segregation studies in larger kindreds to assess their contribution to variable phenotype. A high proportion (∼41%) of unsolved or ambiguous cases suggests novel genetic etiologies that remain to be elucidated.

Reduced frequency and severity of ketoacidosis at diagnosis of childhood type 1 diabetes in Northwest Saudi Arabia

BACKGROUND

Raising the awareness of childhood diabetes symptoms can reduce the frequency of diabetic ketoacidosis (DKA) at onset of type 1 diabetes (T1D). However, data on the effectiveness of such interventions are limited. The aim of the study was to describe trends of DKA at onset of childhood T1D during 2005-2014 and assess the impact of a diabetes awareness campaign launched late 2010.

METHODS

Data of children <12 years presented with DKA at diagnosis were analyzed according to age, gender and year of diagnosis. The frequency and severity of DKA before and during the 4 years campaign were compared.

RESULTS

During 2005-2014, 44.9% (243/541) of children diagnosed with T1D presented with DKA. Of these, 22.7% had pH <7.1. In both genders DKA was higher in children <6 years (47.8% vs. 40%; p<0.01) and more severe in <3 years old compared to older children (30% vs. 20%; p<0.01). Following the awareness campaign DKA rate dropped from 48% in 2010 to 39% in 2014 and 15.8% had severe DKA compared to 26.1% in 2005-2010 (p<0.01). This trend was observed in both genders and across age groups. In children <3 years the reduction in DKA frequency and severity was not statistically significant (p=0.15 and p=0.42, respectively).

CONCLUSIONS

In NWSA, the frequency and severity of DKA at onset of childhood T1D were reduced following 4 years awareness campaign; but the rate is still high. Maintaining the campaign may result in further improvement following a longer period of observation.

Expanding the Clinical Spectrum Associated With GLIS3 Mutations

CONTEXT

GLIS3 (GLI-similar 3) is a member of the GLI-similar zinc finger protein family encoding for a nuclear protein with 5 C2H2-type zinc finger domains. The protein is expressed early in embryogenesis and plays a critical role as both a repressor and activator of transcription. Human GLIS3 mutations are extremely rare.

OBJECTIVE

The purpose of this article was determine the phenotypic presentation of 12 patients with a variety of GLIS3 mutations.

METHODS

GLIS3 gene mutations were sought by PCR amplification and sequence analysis of exons 1 to 11. Clinical information was provided by the referring clinicians and subsequently using a questionnaire circulated to gain further information.

RESULTS

We report the first case of a patient with a compound heterozygous mutation in GLIS3 who did not present with congenital hypothyroidism. All patients presented with neonatal diabetes with a range of insulin sensitivities. Thyroid disease varied among patients. Hepatic and renal disease was common with liver dysfunction ranging from hepatitis to cirrhosis; cystic dysplasia was the most common renal manifestation. We describe new presenting features in patients with GLIS3 mutations, including craniosynostosis, hiatus hernia, atrial septal defect, splenic cyst, and choanal atresia and confirm further cases with sensorineural deafness and exocrine pancreatic insufficiency.

CONCLUSION

We report new findings within the GLIS3 phenotype, further extending the spectrum of abnormalities associated with GLIS3 mutations and providing novel insights into the role of GLIS3 in human physiological development. All but 2 of the patients within our cohort are still alive, and we describe the first patient to live to adulthood with a GLIS3 mutation, suggesting that even patients with a severe GLIS3 phenotype may have a longer life expectancy than originally described.

Liver disease and other comorbidities in Wolcott-Rallison syndrome: different phenotype and variable associations in a large cohort

BACKGROUND

Wolcott-Rallison syndrome (WRS) is caused by recessive EIF2AK3 mutations and characterized by early-onset diabetes and skeletal dysplasia. Hepatic dysfunction has been reported in 60% of patients.

AIMS

To describe a cohort of WRS patients and discuss the pattern and management of their liver disease.

METHODS

Detailed phenotyping and direct sequencing of EIF2AK3 gene were conducted in all patients.

RESULTS

Twenty-eight genetically confirmed patients (67% male; mean age 4.6 years) were identified. 17 different EIF2AK3 mutations were detected, of which 2 were novel. The p.S991N mutation was associated with prolonged survival and p.I650T with delayed onset. All patients presented before 25 months with diabetes with variation in the frequency and severity of 10 other features. Liver disease, first manifested as non-autoimmune hepatitis, was the commonest extra-pancreatic feature identified in 85.7% (24/28). 22/24 had at least one episode of acute hepatic failure which was the cause of death in all deceased patients (13/28). One child was treated by liver transplantation and had no liver disease and better diabetes control for the following 6 years.

CONCLUSIONS

Liver disease in WRS is more frequent than previously described and carries high mortality. The first experience with liver transplantation in WRS is encouraging.

Neonatal adrenal hematoma with urinary tract infection: risk factor or a chance association?

Neonatal adrenal hematoma is a rare finding that can be discovered incidentally or presents with various symptoms. However, urinary tract infection (UTI) has not been reported in association with this condition. We report on a 4-week old child with massive unilateral adrenal hematoma discovered incidentally during a routine abdominal ultrasound scan for UTI. The mass resolved spontaneously after several months with no complications. The diagnosis and management of infantile suprarenal mass and the possible link between this child's UTI and the adrenal hematoma are discussed.

Familial glucocorticoid deficiency: a diagnostic challenge during acute illness

Familial glucocorticoid deficiency (FGD) is a heterogeneous condition of isolated glucocorticoid deficiency due to adrenocorticotropic hormone (ACTH) resistance. Patients have adrenal failure with normal electrolytes. We report two Arab children with different forms of FGD, in whom the diagnosis was initially masked by their acute illness and discuss the reasons for the delay in the diagnosis of FGD in both patients. Patient 1 presented at 12 days with Serratia sepsis. She received hydrocortisone for septic shock and needed dexamethasone courses to wean her off ventilation. At 13 weeks, she had normal electrolytes, low cortisol and high ACTH in keeping with FGD. A homozygous missense mutation (T159) in MC2R confirmed the diagnosis of FGD type 1. Patient 2 was admitted at 4.5 years, with an acute exacerbation of chronic asthma. At presentation, he had hypotension, hypoglycaemia and normal electrolytes. He was given IV hydrocortisone to treat his severe asthma, and his lip hyperpigmentation was thought to be central cyanosis. Two weeks later, his lips remained dark, and cortisol was low, with markedly elevated ACTH. Family history revealed a sister aged 22 years with cerebral palsy and a healthy 15-year-old brother, who were both severely pigmented with high ACTH levels. The diagnosis of FGD type 2 was confirmed by identifying a homozygous missense mutation (p.Y59D) in MRAP in the three siblings.

CONCLUSIONS

FGD can be easily overlooked during acute illness. In a sick child, paired measurement of serum cortisol with ACTH prior to starting steroid therapy would be useful in making the diagnosis of FGD.

Frequency and spectrum of Wolcott-Rallison syndrome in Saudi Arabia: a systematic review

BACKGROUND

Wolcott-Rallison syndrome (WRS) is caused by recessive EIF2AK3 gene mutations and characterized by permanent neonatal diabetes (PNDM), skeletal dysplasia, and recurrent hepatitis. The frequency of this rare syndrome is largely unknown.

OBJECTIVES

To define the frequency and spectrum of WRS in the Kingdom of Saudi Arabia (KSA) based on published data.

METHODS

The Medline database was searched for published articles on WRS. The number of reported cases from KSA was compared to the total number of WRS cases reported worldwide. The genotype and phenotype of WRS patients from KSA were reviewed.

RESULTS

Ten articles describing 23 WRS patients from 12 Saudi families from 1995 to 2012 were identified. This figure accounts for 27.7% (23/83) of the patients and 22.2% (12/54) of the families with WRS reported worldwide until January 2013. All Saudi patients with WRS presented with PNDM, and they represent 59% of all PNDM cases from WRS. At reporting, 73% of patients experienced recurrent hepatitis, 56.5% had skeletal abnormalities, and 39.1% of them were dead. There was a variation in the phenotype even between affected siblings. Genetic diagnosis was confirmed in all 12 families with no correlation between the genotype and phenotype. Eight of the nine EIF2AK3 mutations were only reported in these families, and one was shared with a patient from Qatar, a neighboring Arab state.

CONCLUSIONS

No study on the frequency of WRS has been published. However, the available data indicate that KSA has the largest collection of patients with WRS worldwide, and nine of the identifiable EIF2AK3 mutations appear to be confined to Arabs. Establishing a national or international registry for WRS would provide more reliable data on this rare condition.

Variable phenotype in five patients with Wolcott-Rallison syndrome due to the same EIF2AK3 (c.1259delA) mutation

Wolcott-Rallison syndrome (WRS) is a rare condition characterized by permanent neonatal diabetes (PND), skeletal dysplasia, and recurrent hepatitis. Other features, including central hypothyroidism, have been reported. We compared the phenotype of five patients from two families with WRS caused by the same EIF2AK3 mutation who have been followed up since diagnosis. Direct sequencing of the EIF2AK3 gene identified a homozygous frameshift mutation (c.1259delA) in all patients that has been reported only in these families. All patients presented with PND and four experienced recurrent hepatitis. A 3.5-year-old girl has isolated PND, whereas her younger sister has typical WRS features. Two children developed skeletal abnormalities and two had transient central hypothyroidism. Other reported features of WRS were not detected. The EIF2AK3 c.1259delA mutation results in a variable phenotype, ranging from isolated PND to typical WRS. Thyroid dysfunction in WRS is a transient phenomenon reflecting euthyroid sickness.

Endocrinopathies in beta-thalassemia major. Prevalence, risk factors, and age at diagnosis in Northwest Saudi Arabia

OBJECTIVE

To define the prevalence, risk factors, and age at diagnosis of endocrinopathies in beta-thalassemia major (BTM) in Northwest Saudi Arabia.

METHODS

This retrospective cross-sectional study included patients with BTM attending a combined endocrine-hematology clinic in Al-Madinah, Kingdom of Saudi Arabia from March 2009 to December 2010. Clinical and biochemical data from the initial clinic visits were used to define the prevalence and age of diagnosis of endocrinopathies. Demographic and laboratory variables were analyzed to identify significant risk factors.

RESULTS

Eighty-one patients (42 males), aged 2-28 years were screened. Thirty-eight of them (46.9%) had at least one endocrinopathy. Of these, 28.9% (11/38) were aged less than 10 years. Hypogonadism was the most common complication detected in 52.7% (19/36) of patients of pubertal age group and 23.4% (19/81), of all cohort followed by short stature in 20.9% (17/81), subclinical hypothyroidism in 14.8% (12/81) and hypoparathyroidism in 11.1% (9/81). Patients with endocrinopathies were older (p=0.001), had longer duration of transfusion (p=0.001), and were started at a late age on chelation than those without endocrinopathies (p=0.07). Recent serum ferritin was poorly correlated to endocrinopathies (p=0.15).

CONCLUSION

Endocrinopathies are common in our BTM cohort, and patients with this condition benefit from regular endocrine screening within the first 10 years of life. Although endocrinopathies were more prevalent in older patients; further, longitudinal studies are needed to define the exact age of onset and independent risk factors for these complications.

Incidence, genetics, and clinical phenotype of permanent neonatal diabetes mellitus in northwest Saudi Arabia

BACKGROUND

Permanent neonatal diabetes mellitus (PNDM) in European population has an incidence of at least 1 in 260 000 live births and is most commonly due to mutations in KCNJ11 and ABCC8. However, data on this condition in other populations are limited.

OBJECTIVE

To define the incidence, genetic aetiology, and clinical phenotype of PNDM in Al-Madinah region, northwest Saudi Arabia.

METHODS

Patients with PNDM diagnosed between 2001 and 2010 were identified and clinically phenotyped. Sequencing of KCNJ11, ABCC8, and INS were performed initially on all subjects, and EIF2AK3, GLIS3, SLC2A2, SLC19A2, GCK, IPF1, and NEUROD1 genes were sequenced according to the clinical phenotype.

RESULTS

In total, 17 patients from 11 consanguineous families were diagnosed with PNDM and the incidence was 1 in 21 196 live births. Six different mutations in four genes were identified, of which two GLIS3 and one SLC2A2 were novel and no patient had KCNJ11, ABCC8, or INS mutations. Fourteen (82.4%) patients had identifiable genetic aetiology and their PNDM was part of known autosomal-recessive syndromes including Wolcott Rallison (41.1%), neonatal diabetes and hypothyroidism (29.4%), Fanconi-Bickel (5.8%), and thiamine-responsive megaloblastic anaemia (5.8%). Two patients with isolated PNDM and one with intermediate developmental delay, epilepsy and neonatal diabetes had no identifiable cause.

CONCLUSIONS

Al-Madinah region has the highest reported incidence of PNDM worldwide. In this region with high consanguinity, PNDM has different genetic aetiology and in the majority of cases presents as a part of rare familial autosomal-recessive syndrome rather than in isolation.

SLC2A2 mutations can cause neonatal diabetes, suggesting GLUT2 may have a role in human insulin secretion

AIMS

The gene SLC2A2 encodes GLUT2, which is found predominantly in pancreas, liver, kidney and intestine. In mice, GLUT2 is the major glucose transporter into pancreatic beta cells, and biallelic Slc2a2 inactivation causes lethal neonatal diabetes. The role of GLUT2 in human beta cells is controversial, and biallelic SLC2A2 mutations cause Fanconi-Bickel syndrome (FBS), with diabetes rarely reported. We investigated the potential role of GLUT2 in the neonatal period by testing whether SLC2A2 mutations can present with neonatal diabetes before the clinical features of FBS appear.

METHODS

We studied SLC2A2 in patients with transient neonatal diabetes mellitus (TNDM; n = 25) or permanent neonatal diabetes mellitus (PNDM; n = 79) in whom we had excluded the common genetic causes of neonatal diabetes, using a combined approach of sequencing and homozygosity mapping.

RESULTS

Of 104 patients, five (5%) were found to have homozygous SLC2A2 mutations, including four novel mutations (S203R, M376R, c.963+1G>A, F114LfsX16). Four out of five patients with SLC2A2 mutations presented with isolated diabetes and later developed features of FBS. Four out of five patients had TNDM (16% of our TNDM cohort of unknown aetiology). One patient with PNDM remains on insulin at 28 months.

CONCLUSIONS

SLC2A2 mutations are an autosomal recessive cause of neonatal diabetes that should be considered in consanguineous families or those with TNDM, after excluding common causes, even in the absence of features of FBS. The finding that patients with homozygous SLC2A2 mutations can have neonatal diabetes supports a role for GLUT2 in the human beta cell.

Permanent neonatal diabetes: different aetiology in Arabs compared to Europeans

OBJECTIVE

Mutations in the KCNJ11 and ABCC8 genes that encode the pancreatic K(ATP) channel are the commonest cause of permanent neonatal diabetes mellitus (PNDM). The authors aimed to define the genetic causes of PNDM in a large cohort of Arab patients and compare them with a British cohort tested in the same laboratory.

DESIGN

Retrospective observational study.

SETTING

International genetics centre.

PATIENTS

Arab and British subjects with PNDM who were referred for genetic testing over the same period.

INTERVENTION

Comparison of genotypes and phenotypes between the two cohorts.

MAIN OUTCOME MEASURES

The aetiology and phenotype of PNDM in an Arab compared to a British cohort.

RESULTS

88 Arab and 77 British probands were referred between 2006 and 2011, inclusive. Consanguinity was higher among Arabs (63.6% vs 10.4%) and a higher percentage had a genetic diagnosis compared to the British cohort (63.6% vs 41.6%). Recessive EIF2AK3 gene mutations were the commonest cause of PNDM in the Arab cohort (22.7%) followed by INS (12.5%), and KCNJ11 and GCK (5.7% each), whereas K(ATP) channel mutations were the commonest cause (29.9%) in the British cohort. In 37.5% of Arab patients PNDM was part of a genetic syndrome compared to 7.8% of the British cohort.

CONCLUSION

PNDM in the Arab population has a different genetic spectrum compared to British patients where KATP channel mutations are the commonest cause, similar to other European populations. In Arabs, PNDM is more likely to be part of a recessively inherited syndrome, possibly due to the higher rate of consanguinity.

Recessive SLC19A2 mutations are a cause of neonatal diabetes mellitus in thiamine-responsive megaloblastic anaemia

Permanent neonatal diabetes mellitus (PNDM) is diagnosed within the first 6 months of life, and is usually monogenic in origin. Heterozygous mutations in ABCC8, KCNJ11, and INS genes account for around half of cases of PNDM; mutations in 10 further genes account for a further 10%, and the remaining 40% of cases are currently without a molecular genetic diagnosis. Thiamine-responsive megaloblastic anaemia (TRMA), due to mutations in the thiamine transporter SLC19A2, is associated with the classical clinical triad of diabetes, deafness, and megaloblastic anaemia. Diabetes in this condition is well described in infancy but has only very rarely been reported in association with neonatal diabetes. We used a combination of homozygosity mapping and evaluation of clinical information to identify cases of TRMA from our cohort of patients with PNDM. Homozygous mutations in SLC19A2 were identified in three cases in which diabetes presented in the first 6 months of life, and a further two cases in which diabetes presented between 6 and 12 months of age. We noted the presence of a significant neurological disorder in four of the five cases in our series, prompting us to examine the incidence of these and other non-classical clinical features in TRMA. From 30 cases reported in the literature, we found significant neurological deficit (stroke, focal, or generalized epilepsy) in 27%, visual system disturbance in 43%, and cardiac abnormalities in 27% of cases. TRMA should be considered in the differential diagnosis of diabetes presenting in the neonatal period.

High incidence of childhood type 1 diabetes in Al-Madinah, North West Saudi Arabia (2004-2009)

BACKGROUND

There is a geographical variation in the incidence of childhood type 1 diabetes mellitus (T1DM) with a steady increase reported from some countries. However, data on the incidence of childhood T1DM in Kingdom of Saudi Arabia are limited.

OBJECTIVE

To identify the incidence rate (IR) and epidemiological trends of childhood T1DM in the largest city of northwest Saudi Arabia.

METHODS

All patients with newly diagnosed T1DM aged 0-12 yr living in the city between 2004 and 2009 were identified from different sources. The data were analyzed according to age, sex, and month of presentation.

RESULTS

In total, 419 patients (249 girls) were diagnosed between 2004 and 2009 inclusive. The mean age at diagnosis was 6.9 ± 3.5 yr. The mean annual age-standardized IR was 29.0 (95% confidence interval 26.0-32.0). The incidence was significantly higher in the 10-12-yr age group than in younger children (p < 0.001) and higher in girls than in boys (33.0 vs. 22.2 per 100 000; p < 0.001). There was no significant increase in the annual incidence during the 6-yr period (p = 0.68) and more cases were diagnosed during autumn and winter months (p = 0.002).

CONCLUSIONS

Al-Madinah city has the highest reported incidence of childhood T1DM in the Middle East and North Africa region. Further studies to identify the reasons for this high incidence are needed.

Response to oral gliclazide in a pre-pubertal child with hepatic nuclear factor-1 alpha maturity onset diabetes of the young

The term "maturity onset diabetes of the young" (MODY) describes a heterogeneous group of monogenic diabetes of which hepatic nuclear factor-1 alpha (HNF-1α) MODY is the most common. Patients with HNF-1α mutations typically present after puberty, and oral sulfonylureas (SU) have been shown to be effective in adults with this condition. A 7-year-old boy presented with asymptomatic hyperglycemia ranging between 6.2 and 10.1 mmol/L and glycosuria for nearly a year. The child's initial HbA 1c was 6.9% and the pancreatic Islet cell autoantibodies were negative. His response to the oral glucose tolerance test (OGTT) showed a large increment of glucose from basal level of 7.7 to 21.1 mmol/L in 120 min. The mild presentation, family history, and negative autoantibodies were suggestive of HNF-1α MODY, which was confirmed by mutation analysis. Initial management with diet alone was not sufficient, but he responded well to 20 mg oral gliclazide once a day with an improvement of HbA 1C from 7.2% to 6.5% within 3 months of treatment. The case is an illustration of the clinical utility of molecular genetic tests in the management of childhood diabetes.

Missense mutations in the melanocortin 2 receptor accessory protein that lead to late onset familial glucocorticoid deficiency type 2

BACKGROUND

Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by isolated glucocorticoid deficiency. Mutations in the ACTH receptor [melanocortin 2 receptor (MC2R)] or the MC2R accessory protein (MRAP) cause FGD types 1 and 2, respectively. Typically, type 2 patients present early (median age, 0.1 yr), and no patient reported to date has presented after 1.6 yr.

AIM

The aim of this study was to investigate the cause of disease in two families with late-onset FGD.

PATIENTS

The proband in family 1 was diagnosed at age 4 yr. Family review revealed two older siblings with undiagnosed FGD. One sibling was well, whereas the second had cerebral palsy secondary to hypoglycemic seizures. The proband in family 2 was diagnosed at age 18 yr with symptoms of fatigue, weight loss, and depression.

METHODS

The coding exons of MC2R and MRAP were sequenced. ACTH dose-response curves were generated for MC2R when transfected with wild-type or mutant MRAP constructs using HEK293 cells. MC2R trafficking with both mutant MRAPs was investigated using immunocytochemistry.

RESULTS

MRAP gene analysis identified two novel homozygous missense mutations, c.175T>G (pY59D) in family 1 and c.76T>C (p.V26A) in family 2. In vitro analysis showed that the Y59D mutant had significant impairment of cAMP generation, and both mutants caused a shift in the dose-response curve to the right when compared to wild type. Immunocytochemistry showed normal trafficking of MC2R when transfected with both mutant MRAPs, indicating a probable signaling defect.

CONCLUSION

These results indicate that missense MRAP mutations present with a variable phenotype of ACTH resistance and can present late in life.