Relative Frequency of Islet Autoimmunity in Children and Adolescents with Autoimmune Thyroid Disease

Objective: The aim of the present study was to investigate islet autoimmunity and susceptibility to type 1 diabetes (T1D) in children/adolescents with autoimmune thyroid disease (AITD, and in family members of AITD patients with islet autoimmunity. Methods: Islet-cell cytoplasmic, glutamic-acid decarboxylase, and tyrosine-phosphatase autoantibodies (AAbs) were measured in 161 AITD patients [127 with autoimmune thyroiditis (AT); 34 with Graves' disease (GD)], 20 family members of AITD patients with islet autoimmunity, and 155 age-matched controls. Results: Islet autoimmunity was found in 10.6% of AITD patients, significantly more frequent than in controls (1.9%; p=0.002). A higher prevalence of islet AAbs was found in females with AITD (p=0.011) but not in males (p=0.16) and in AT (p=0.013) but not in GD patients (p=0.19), compared to corresponding controls. Two or three islet AAbs were found concurrently in six AITD patients with islet autoimmunity. They all developed T1D and had significantly higher islet AAbs titers (p=0.01) than AITD patients with single islet AAbs but normal glucose metabolism. T1D was found in 3.7% of AITD patients compared to 0.2% of the age-matched, general Croatian population. Islet AAbs were found in 5/20 family members of AITD patients with islet autoimmunity, among whom two developed T1D. None of the controls was positive for more than one islet AAb or developed T1D. Conclusion: Children/adolescents with AITD, particularly females and patients with AT, appear to represent a risk group for islet autoimmunity and T1D, as do family members of AITD patients with positive islet AAbs. However, these findings should be validated in larger studies.

Pathogenic Variants in GPC4 Cause Keipert Syndrome.

Glypicans are a family of cell-surface heparan sulfate proteoglycans that regulate growth-factor signaling during development and are thought to play a role in the regulation of morphogenesis. Whole-exome sequencing of the Australian family that defined Keipert syndrome (nasodigitoacoustic syndrome) identified a hemizygous truncating variant in the gene encoding glypican 4 (GPC4). This variant, located in the final exon of GPC4, results in premature termination of the protein 51 amino acid residues prior to the stop codon, and in concomitant loss of functionally important N-linked glycosylation (Asn514) and glycosylphosphatidylinositol (GPI) anchor (Ser529) sites. We subsequently identified seven affected males from five additional kindreds with novel and predicted pathogenic variants in GPC4. Segregation analysis and X-inactivation studies in carrier females provided supportive evidence that the GPC4 variants caused the condition. Furthermore, functional studies of recombinant protein suggested that the truncated proteins p.Gln506∗ and p.Glu496∗ were less stable than the wild type. Clinical features of Keipert syndrome included a prominent forehead, a flat midface, hypertelorism, a broad nose, downturned corners of mouth, and digital abnormalities, whereas cognitive impairment and deafness were variable features. Studies of Gpc4 knockout mice showed evidence of the two primary features of Keipert syndrome: craniofacial abnormalities and digital abnormalities. Phylogenetic analysis demonstrated that GPC4 is most closely related to GPC6, which is associated with a bone dysplasia that has a phenotypic overlap with Keipert syndrome. Overall, we have shown that pathogenic variants in GPC4 cause a loss of function that results in Keipert syndrome, making GPC4 the third human glypican to be linked to a genetic syndrome.

The effect of 17 years of increased salt iodization on the prevalence and nature of goiter in Croatian schoolchildren.

Background High goiter prevalence caused by iodine deficiency (medium content 5.6 mg potassium iodide [KI]/kg of salt, median urine iodine concentration [UIC] 68 µg/L) in Croatia was observed in 1991 and 1995 when salt was iodized with 10 mg KI/kg. A new regulation introduced in 1996, specified 25 mg KI/kg of salt resulting in an increase of median UIC to 248 µg/L. Afterwards, goiter prevalence was only assessed in two small studies. Methods In this study, we investigated the prevalence and etiology of goiter in 3594 schoolchildren 17 years after an increase in salt iodization in Croatia. Thyroid size was determined by palpation in 1777 girls and 1817 boys aged 10-18 years. In goitrous children, a thyroid ultrasound and thyroid-stimulating hormone, free thyroxine (fT4), free triiodothyronine (fT3), thyroid peroxidase (TPO) and thyroglobulin (TG) antibody measurements were performed. Results Goiter was found in 32 children (0.89% vs. 2.8% in 1991, p<0.00001 and 27% in 1995, p<0.00001), simple goiter (SG) in 18/32 (56%) goitrous children vs. 126/152 (82.8%) in 1991 p<0.00001, autoimmune thyroiditis (AT) in 13/32 (40.6%) vs. 19/152 (12.5%) in 1991 p<0.0009, nodules in four: two cysts, toxic adenoma and carcinoma (in 1991 two adenomas and one cyst), Graves' disease was not found (four in 1991). Subclinical hypothyroidism was found in three children. Thyroid disease was diagnosed in four of 32 children before the investigation. Increased iodine supply decreased goiter prevalence and SG/AT ratio in goitrous patients. Conclusions As thyroid abnormalities were found in 0.89% of children and some required treatment, thyroid examination is important in apparently healthy children regardless of sufficient iodization.

Testicular adrenal rest tumors in congenital adrenal hyperplasia-cross-sectional study of 51 Croatian male patients.

Testicular adrenal rest tumors (TARTs) are common cause of infertility in males with congenital adrenal hyperplasia (CAH). We studied the role of genotype and disease regulation on TART development, their impact on gonadal function, and frequency in 47 21-hydroxylase deficiency (21-OHD) and four 11-hydroxylase deficiency (11-OHD) male patients. Testicular ultrasound (TU), genotype, hormonal measurement in 51, and spermiogram in five patients were performed. TARTs were detected in 14 SW21-OHD and one 11-OHD patient: 1/8 patients aged <7 years (1.8 years old is the youngest), 1/8 patients aged <12 years, 5/17 patients aged <18 years, and in 8/18 adults. All 21-OHD TART patients had exclusively severe mutations of CYP21A2 gene. Poor hormonal control in 8/15 patients with and 12/36 patients without TART indicates correlation of tumor development with poor disease control. None of the TART patients fathered a child. Low inhibin-B was found in 7/15 TART patients. Azoospermia was found in four and oligoasthenozoospermia in one patient. CONCLUSION: TART was detected exclusively in patients with severe CYP21A2 mutations. Disease regulation plays a role in development of TART that impairs testicular function and increases the risk of infertility. Screening for TART by TU is indicated from early childhood. What is Known: • Due to improved diagnostic and therapeutic possibilities, majority of the male patients with congenital adrenal hyperplasia nowadays reach adulthood and screening for long-term complications is becoming more important. • Testicular adrenal rest tumors (TARTs) are common cause of infertility and impaired gonadal function in males with CAH. What is New: • A 1.8-year-old boy described in this paper is the youngest reported patient with TART. • Screening for TART by testicular ultrasound from early childhood, especially in patients with severe CYP21A mutations, is recommended.

Primary hypothyroidism and nipple hypoplasia in a girl with Wolcott-Rallison syndrome.

UNLABELLED: Wolcott-Rallison syndrome (WRS), caused by mutation in the EIF2AK3 gene encoding the PERK enzyme, is the most common cause of permanent neonatal diabetes mellitus (PNDM) in consanguineous families and isolated populations. Besides PNDM, it also includes skeletal abnormalities, liver and renal dysfunction, and other inconsistently present features. We present two siblings, who are WRS patients, and are Albanians from Kosovo born to unrelated parents. The older sister presented with PNDM, exocrine pancreatic insufficiency, short stature, microcephaly, normocytic anemia, delay in speech development, skeletal abnormalities, primary hypothyroidism, and hypoplastic nipples. Sequencing of the EIF2AK3 gene identified a homozygous mutation R902X in exon 13. The younger brother was diagnosed with PNDM and died from hepatic failure suggesting that he has been suffering from WRS as well. Including one previously reported patient from Kosovo carrying the same homozygous mutation, there are three WRS patients from this very small, ethnically homogenous region suggesting founder effect in this population. CONCLUSION: We postulate that thyroid hypoplasia with primary subclinical hypothyroidism already reported in two WRS patients and nipple hypoplasia could also be the phenotypic reflection of the mutation of pleiotropic EIF2AK3 gene in secretory cells.

[Low doses of sulphonyluria as a successful replacement for insulin therapy in a patient with neonatal diabetes due to a mutation of KCNJ11 gene encoding Kir6.2]. / Niske doze sulfonilureje kao uspjesna zamjena za inzulin u lijecenju neonatalnog dijabetesa uzrokovanog aktivirajucom mutacijom Kir6.2.

Neonatal diabetes mellitus is a rare metabolic disorder with an estimated incidence of 1:300.000 to 400.000 newborns, and less than 50% of the neonates have permanent neonatal diabetes mellitus (PNDM). Recently, activating mutation in the KCNJ11 gene encoding Kir6.2 subunit of the adenosin triphosphate-sensitive potassium (K(ATP)) channel has been described as the most frequent cause of PNDM. Under physiological circumstances K(ATP) channel closure plays a central role in glucose-stimulated insulin secretion from pancreatic beta cells. Sulphonylurea drugs stimulate insulin secretion by binding to and closing K(ATP) channels and thus bypassing beta cell metabolism stimulate the same chain of reactions as glucose. We describe a boy diagnosed with PNDM at the age of 3 months when insulin therapy was started, and at the age of 4.5 years KCNJ11 gene was sequenced and found that the boy carried a de novo activating R201H mutation. Insulin therapy was successfully switched to low doses of oral glibenclamide. Accordingly, it is important to emphasize that every person diagnosed with diabetes before six months of life, however old they actually are, should be tested for K(ATP) mutations which is offered via the website www.diabetesgenes.org.

[Three-year-old boy--a homozygote for familiar hypercholesterolemia]. / Trogodisnji djecak--homozigot za porodicnu hiperkolesterolemiju.

Homozygous familial hypercholesterolemia (FH) is a rare autosomal dominant disorder caused by mutations in the low-density-lipoprotein (LDL) receptor gene. It occurs with a frequency of approximately 1 per million persons world-wide. Clinically, homozygous FH is associated with extremely elevated levels of LDL cholesterol and cutaneous xanthomas that develop in early childhood. These children are at risk of extremely early coronary events and death from myocardial infarction caused by premature generalized atherosclerosis. Their medical treatment is very complex, associated with various problems and complications. We describe a 3-year-old boy with clinical signs of homozygous FH (elevated LDL-cholesterol levels and xanthomas). Heterozygous hypercholesterolemia was found in his parents and some other family members. The boy has been treated with simvastatin and atorvastatin, but without reaching the treatment goals. LDL apheresis is planned as the treatment of choice for homozygous children with FH.

Successful treatment of diffuse large B-cell non-hodgkin lymphoma with modified CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy and rituximab in a patient with Nijmegen syndrome.

A 17-year-old Croatian boy with Nijmegen breakage syndrome (NBS) who developed diffuse large B-cell non-Hodgkin lymphoma is presented. The majority of the patients with this rare autosomal recessive disease are of Slavic origin and, in most of them, the disease is caused by NBS1 mutation 657del5, as was found in our patient. Nijmegen breakage syndrome is characterized by microcephaly, growth retardation, abnormal facial appearance, spontaneous chromosomal rearrangements, immunodeficiency, and a high predisposition to cancer development, predominantly lymphoma. Because of increased sensitivity to radiation therapy and chemotherapy, the treatment of malignancies in patients with NBS can be difficult. To our knowledge, our patient is the first with NBS reported in the literature who was successfully treated for diffuse large B-cell lymphoma with the anti-CD20 monoclonal antibody rituximab in addition to a modified dose of CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy. He has been in complete remission for 3 years after finishing the treatment.

Five patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (one with associated neuroblastoma) discovered in three generations of one family.

BACKGROUND: Most patients with 21-hydroxylase deficiency (21-OHD) are compound heterozygous carriers. Their phenotype usually reflects a less severe allelic mutation, although discordance between the genotype and the phenotype has been observed. CASE REPORT: We present 5 patients with congenital adrenal hyperplasia (CAH) due to 21-OHD belonging to the 3 generations of the same family (grandmother, parents and their 2 children). As each patient carries at least one mild mutation of the CYP21 gene, their genotypes correspond to nonclassical CAH. The propositus is the older brother, who is compound heterozygous with a mild and severe CYP21 mutation (P30L/R356W). In spite of one mild CYP21 mutation, he presented with the clinical picture of a simple virilizing form of 21-OHD and required glucocorticoid replacement therapy from the age of 4. Both probands' parents are compound heterozygous carriers of different CYP21 gene mutations causing various degrees of enzymatic activity impairment, which explains the different genotypes and phenotypes in their offspring. The probands' mother, besides the nonclassical 21-OHD, also had neuroblastoma of the adrenal gland. CONCLUSION: The potential discordance between the genotype and the phenotype in some patients with CAH is emphasized. The existence of a mild CYP21 mutation P30L in a compound heterozygous with CAH might be associated with progressive virilization requiring glucocorticoid therapy from early childhood. The occurrence of neuroblastoma with 21-OHD may support the hypothesis that an impairment in the synthesis and secretion of glucocorticoids may play role in the development and functioning of the adrenal medulla.

[Primary pigmented nodular adrenocortical disease as cause of Cushing's syndrome associated with Carney complex]. / Primarna pigmentna nodularna adrenokortikalna bolest kao uzrok Cushingova sindroma u sklopu Carneyeva kompleksa.

We report a 11-year-old girl and two 14-year-old boys with Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). In these patients, hypercortisolism is a consequence of autonomous cortisol secretion from adrenal glands and is ACTH-independent. Besides PPNAD, the girl had lentigines, spotty pigmentation on her bucal mucosa and lips and she also had schwannoma. One of the reported boys had prolactinoma. Considering this, those two patients fulfill the criteria for Carney complex which is a type of multiple endocrine neoplasia syndromes inherited in an autosomal dominant trait. The other boy had PPNAD but no other obvious signs of Carney complex were noticed. Family study didn't reveal any clinical or laboratory signs of Carney complex in our patients' first relatives. All of our patients underwent bilateral adrenalectomy (in one of the boys laparoscopic surgery was performed). Glucocorticoid and mineralocorticoid substitution has been started. Adrenal glands were macroscopically normal but pathohistological analysis confirmed the diagnosis of PPNAD.