Growth hormone deficiency in patients with 22q11.2 deletion: expanding the phenotype

An Endocrinological Perspective on 22q11.2 Deletion Syndrome: A Single-center Experience

Objective

22q11.2 deletion syndrome (22q11.2 DS) is the most common chromosomal microdeletion disorder. Associated problems in 22q11.2 DS may include cardiac abnormalities, immune dysfunction, facial dysmorphism, with endocrine, genitourinary and gastrointestinal problems, and developmental delay. The aim of this study was to evaluate and present all endocrinological findings of patients with 22q11.2 DS from a single center.

Methods

All participants had confirmed 22q11.2 DS by fluorescence in situ hybridization with hypoparathyroidism. Data were retrieved by retrospective review of patient records.

Results

A total of 17 patients were reviewed. On physical examination, all patients had similar dysmorphic features. The median age at diagnosis was 45 days (1 day-13 years). Most cases (64.7%, 11/17) were diagnosed with hypoparathyroidism incidentally after routine tests. At the time of diagnosis, mean calcium was 7.04±0.80 mg/dL, phosphorus was 6.2±1.1 mg/dL, and median parathyroid hormone (PTH) was 11.5 (3.7-47.6) ng/L. Transient hypoparathyroidism was detected in five cases (29.4%). There was no significant difference between patients with permanent or transient hypoparathyroidism regarding gender, age at diagnosis, calcium, phosphorus, and PTH levels. However, vitamin D levels were significantly lower in the transient group (p=0.036). During follow-up, short stature, obesity, and type 2 diabetes mellitus were absent. Thyroid autoantibodies were detected in two patients with normal thyroid function tests. Despite there being no pathological short stature, final stature was shorter than the general population (mean height standard deviation score: -0.94±0.83).

Conclusion

Hypocalcemia may be detected during acute illness in some cases where hypocalcemia appears at later ages. There was no significant difference between permanent and transient hypoparathyroidism cases in terms of PTH level. Recognition of the more specific facial findings is important to trigger investigation of genetic variants, additional anomalies, and for follow-up.

Updated clinical practice recommendations for managing children with 22q11.2 deletion syndrome

This review aimed to update the clinical practice guidelines for managing children and adolescents with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society, the international scientific organization studying chromosome 22q11.2 differences and related conditions, recruited expert clinicians worldwide to revise the original 2011 pediatric clinical practice guidelines in a stepwise process: (1) a systematic literature search (1992-2021), (2) study selection and data extraction by clinical experts from 9 different countries, covering 24 subspecialties, and (3) creation of a draft consensus document based on the literature and expert opinion, which was further shaped by survey results from family support organizations regarding perceived needs. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text reviews, including 1545 meeting criteria for potential relevance to clinical care of children and adolescents. Informed by the available literature, recommendations were formulated. Given evidence base limitations, multidisciplinary recommendations represent consensus statements of good practice for this evolving field. These recommendations provide contemporary guidance for evaluation, surveillance, and management of the many 22q11.2DS-associated physical, cognitive, behavioral, and psychiatric morbidities while addressing important genetic counseling and psychosocial issues.

Endocrine and Growth Disorders in Taiwanese Children With 22q11.2 Deletion Syndrome

BACKGROUND

Endocrine disorders are common in patients with 22q11.2 deletion syndrome (22q11.2DS). This study aimed to elucidate the clinical manifestations of endocrine disorders, including parathyroid, thyroid and growth disorders, in Taiwanese patients with 22q11.2DS.

METHODS

From 1994 to 2020, the medical records of 138 patients with 22q11.2DS diagnosed at a tertiary referral medical center in Taiwan were thoroughly reviewed retrospectively.

RESULTS

Hypocalcemia was detected in 57 of 135 patients (42%); 33 of 104 patients (32%) had hypoparathyroidism, and in 87% of them, hypocalcemia was detected before the age of one. Most patients had precipitating stressors during symptomatic hypocalcemic episodes. Eighteen of 29 patients had overt hypoparathyroidism at the last visit: 11 had persistent hypoparathyroidism and the other seven had recurrent hypoparathyroidism. Four of 84 patients had thyroid disorders, including thyroid developmental anomalies in two, dyshormonogenesis in one and Graves' disease in one. Fifty of 126 patients (40%) had short stature. Age (odds ratio (OR) 0.91; 95% confidence interval (CI) 0.86-0.96; P<0.001) and airway anomalies (OR 2.75; 95% CI 1.04-7.31; P<0.05) were significant risk factors for short stature in multivariate logistic regression model. Twenty-eight of the 30 patients with airway anomalies were associated with severe congenital heart disease. Adult height standard deviation score (SDS) in 19 patients was significantly lower than target height SDS (-1.15 ± 0.90 vs -0.08 ± 0.65, P<0.001).

CONCLUSIONS

Hypoparathyroidism is a common endocrine disorder in patients with 22q11.2DS. It is prudent to assess parathyroid function at diagnosis and during follow-up, especially in the presence of stress, to prevent symptomatic hypocalcemia. Although thyroid disorders are not so common as hypoparathyroidism, screening of thyroid dysfunction is justified in these patients. Patients with 22q11.2DS demonstrate a retarded growth pattern with a tendency of catch-up and regular monitoring of growth is indicated.

Ontogeny of the facial phenotypic variability in Mexican patients with 22q11.2 deletion syndrome

Background

22q11.2 deletion syndrome is a medical condition that results from genomic loss at chromosome 22. Affected patients exhibit large variability that ranges from a severe condition to mild symptoms. In addition, the spectrum of clinical features differs among populations and even within family members. The facial features related to this syndrome are not an exception, and although part of its variation arises through development, few studies address this topic in order to understand the intra and inter-population heterogeneities. Here, we analyze the ontogenetic dynamics of facial morphology of Mexican patients with del22q11.2 syndrome.

Methods

Frontal facial photographs of 37 patients (mean age = 7.65 ± 4.21 SE) with del22q11.2DS and 200 control subjects (mean age = 7.69 ± 4.26 SE) were analyzed using geometric morphometric methods. Overall mean shape and size differences between patients and controls were analyzed, as well as differences in ontogenetic trajectories (i.e. development, growth, and allometry).

Results

We found that Mexican patients show typical traits that have been reported for the Caucasian population. Additionally, there were significant differences between groups in the facial shape and size when all the ontogenetic stages were considered together and, along ontogeny. The developmental and allometric trajectories of patients and controls were similar, but they differed in allometric scaling. Finally, patients and controls showed different growth trajectories.

Conclusion

The results suggest that the typical face of patients with del22q11.2DS is established prenatally; nonetheless, the postnatal ontogeny could influence the dysmorphology and its variability through size-related changes.

Eye Signs in Pituitary Disorders

The eye is a vital sense organ and plays a vital role in conveying the underlying physical and mental state of wellbeing of an individual. A comprehensive examination of the eye is often required in patients presenting with systemic complaints. Many endocrine disorders have characteristic manifestations pertaining to the eye, the classical being the exophthalmos in thyrotoxicosis. However, a cursory eye evaluation may lead to the identification of early features that can help in the diagnosis of other endocrine disorders. This is more common in cases of pituitary mass lesions, who often present with the functional hormonal alterations rather than the visual symptoms. The definitive therapy during the late stages of the disease leads to persisting visual disabilities and affects the quality of life. Hence, the endocrinologists and ophthalmologists need to be aware of various ophthalmic features in the pituitary disorders. In this review, we highlight the eye signs in pituitary disorders, along with a brief description of uncommon ocular-pituitary syndromes.

Growth characteristics and endocrine abnormalities in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) has a wide range of clinical features including endocrine abnormalities. We aimed to characterize growth patterns, hypoparathyroidism, and thyroid dysfunction of individuals with 22q11.2DS. Anthropometric and laboratory measurements were obtained from the charts of 48 individuals (males=28, 8.0±6.8 visits/participant) followed at a national 22q11.2DS clinic between 2009 and 2016. Age at diagnosis was 4.3±4.9 years and age at last evaluation 11.2±7.2 years. Median height-SDS was negative at all ages. Height-SDS at last visit was correlated to the midparental height-SDS (r=0.52 P=0.002). Yet, participants did not reach their target height, with a difference of 1.06±1.07 SD (P <0.0001). Height-SDS at last visit of participants with a heart defect was lower compared to participants with a normal heart (-1.5±1.4 vs. -0.6±0.8, P=0.036), with lower height-SDS in the subgroup of participants with severe heart defects (-2.1±1.6, P=0.009). Mean IGF1-SDS was low (-0.99±1.68) but was not correlated with height-SDS. Thirteen patients (27%) had hypoparathyroidism: 10 presented during infancy and 3 during adolescence. Five patients (10.4%, female=4) had thyroid abnormalities. In conclusions, individuals with 22q11.2 DS have a distinct growth pattern consisting of growth restriction at all ages, resulting in final adult height in the low-normal range. Hypoparathyroidism is common and may present during the neonatal period as well as later in life. Thyroid abnormalities may present during childhood, adolescence, or adulthood.

Failure to thrive as presentation in a patient with 22q11.2 microdeletion

BACKGROUND

Abnormalities of chromosome 22q11, including deletions and translocations, have been described in association with different birth defects and malformations occurring in many combinations and degrees of severity.

CASE PRESENTATION

We describe the case of an 8 month-old infant with no dysmorphic signs who showed progressive postnatal growth failure and no chronic systemic diseases. We found a 22q11.2 microdeletion, inherited from the mother, suggesting the diagnosis of DiGeorge syndrome. The patient had an isolated growth hormone (GH) deficiency and a significant increase in linear growth during the first and the second year of GH therapy, and a recovery of weight was shown.

CONCLUSIONS

Sometimes, in infants with growth failure a genetic analysis is strongly suggested, since chromosomal abnormalities may be present.

Velocardiofacial syndrome in Mexican patients: Unusually high prevalence of congenital heart disease

INTRODUCTION

Velocardiofacial syndrome (VCFS) is the most common microdeletion syndrome with an incidence of 1:4000 live births. Its phenotype is highly variable with facial, velopharyngeal, cardiac, endocrine, immunologic and psychiatric abnormalities. It is caused by a microdeletion in chromosome 22q11.2.

OBJECTIVES

We present 7 years of experience evaluating patients with VCFS regarding their main clinical characteristics.

MATERIAL AND METHODS

The patients included were multidisciplinary evaluated and had a positive FISH analysis for del22q11.2.

RESULTS

A total of 62 patients were assessed, a 34 female/28 male ratio was observed with ages ranging from 9 days to 16 years, all but one patient had typical facial features. A diagnosis of congenital heart disease was established in 97% of the patients; other clinical characteristics were identified with different percentages such as cleft palate, and hypocalcaemia. Three cases had a familial presentation.

DISCUSSION

While the clinical findings of this study were in general terms in keeping with the literature, it is interesting the unexpectedly high percentage of congenital heart disease identified in Mexican children with VCFS that also was the main cause for clinical referral.

Rare copy number variants are a common cause of short stature

Human growth has an estimated heritability of about 80%-90%. Nevertheless, the underlying cause of shortness of stature remains unknown in the majority of individuals. Genome-wide association studies (GWAS) showed that both common single nucleotide polymorphisms and copy number variants (CNVs) contribute to height variation under a polygenic model, although explaining only a small fraction of overall genetic variability in the general population. Under the hypothesis that severe forms of growth retardation might also be caused by major gene effects, we searched for rare CNVs in 200 families, 92 sporadic and 108 familial, with idiopathic short stature compared to 820 control individuals. Although similar in number, patients had overall significantly larger CNVs (p-value<1×10(-7)). In a gene-based analysis of all non-polymorphic CNVs>50 kb for gene function, tissue expression, and murine knock-out phenotypes, we identified 10 duplications and 10 deletions ranging in size from 109 kb to 14 Mb, of which 7 were de novo (p<0.03) and 13 inherited from the likewise affected parent but absent in controls. Patients with these likely disease causing 20 CNVs were smaller than the remaining group (p<0.01). Eleven (55%) of these CNVs either overlapped with known microaberration syndromes associated with short stature or contained GWAS loci for height. Haploinsufficiency (HI) score and further expression profiling suggested dosage sensitivity of major growth-related genes at these loci. Overall 10% of patients carried a disease-causing CNV indicating that, like in neurodevelopmental disorders, rare CNVs are a frequent cause of severe growth retardation.

Growth charts for 22q11 deletion syndrome

The purpose of this work was to create growth curves specific to the 22q11.2 deletion syndrome. Growth parameters on 188 patients (86 females, 102 males) followed by a group of three dysmorphologists were collected by retrospective chart review. Growth charts for body mass, length/height, and head circumference were generated using a semi-parametric model with goodness-of-fit tests. The resulting charts show that between 25 and 50% of children with 22q11.2 deletion syndrome fall below the 2nd centile for the normal population for all growth parameters. Establishing norms of growth for 22q11.2 deletion syndrome allows the clinician to identify and investigate those children who deviate substantially from the growth profile of this condition.

Growth in Chilean infants with chromosome 22q11 microdeletion syndrome

Chromosome 22q11 microdeletion syndrome has a wide range of clinical manifestations including congenital heart malformations, palatal defects, endocrine abnormalities, immunologic deficits, learning difficulties, and an increased predisposition to psychiatric disease. Short stature and poor weight gain in infancy are common findings and are usually seen in the absence of hormone deficiencies. An increased frequency of obesity has been observed in adolescents and adults. We generated gender-specific growth curves from 0 to 24 months of age, based on 479 length and 475 weight measurements from 138 Chilean patients with 22q11 deletion. Final adult height and weight on 25 individuals were analyzed. The 10th, 50th, and 90th centile-smoothed curves for infants were built using the LMS method and compared with World Health Organization Child Growth Standards. The 50th centile for length in the deleted patients was slightly lower than the 10th centile of WHO standards in boys and girls. The same was observed for weight, although a trend toward a gradual increase near 2 years of age was observed, particularly in boys. Average adult height was 152 cm (ranging from 143 to 162 cm) in females, corresponding to the 10th centiles of WHO standards, and 166 cm for males (160-172 cm), at the 20th centile of WHO standards. A third of the adult females and none of the males had body mass index (BMI) greater than 25. The curves should be useful to monitor growth in infants with 22q11 microdeletion syndrome.

Syndrome-specific growth charts for 22q11.2 deletion syndrome in Caucasian children

Growth faltering occurs frequently in infancy in the 22q11 Deletion syndrome (22q11 DS). The subsequent course of growth in childhood and outcome for final adult height lacks consensus. We analyzed 5,149 growth data points from 812 Caucasian subjects with 22q11 DS, from neonates to 37 years old. Charts were constructed for height, weight, body mass index, and head circumference (OFC) using the LMS Chart Maker program. These charts were compared with the WHO birth to 4 years growth standard and US CDC 2000 growth reference between 5 and 20 years. Starting from the 50th centile at birth, by 6-9 months of age boys mean height and weight had fallen to the 9th centile, as did girls height but their weight fell less markedly, to the 25th centile. Feeding difficulties were non-contributory. In children under 2 years old with congenital heart disease (CHD) mean weight was -0.5 SD lighter than no CHD. Catch up growth occurred, more rapid in weight than height in boys. Up to 10 years old both sexes tracked between the 9th and 25th centiles. In adolescence, the trend was to overweight rather than obesity. At 19 years mean height was -0.72 SD for boys, -0.89 SD girls. OFC was significantly smaller than the WHO standard in infancy, between the 9th and 25th centile, rising to the 25th centile by 5 years old. Thereafter the mean was close to the 9th centile of the OFC UK growth reference, more prolonged and marked than in previous studies.

[Graves disease and IgA deficiency as manifestations of 22q11.2 deletion syndrome]

The 22q11.2 deletion syndrome (22q11.2DS) is related to a high phenotypic variability including the velocardiofacial/DiGeorge spectrum. Autoimmune, endocrine and immunodeficiency manifestations have been reportedly associated with the syndrome. The objective of this study was to report a case of 22q11.2DS associated with IgA deficiency and Graves disease and review literature in order to verify the frequency of syndrome alterations. Autoimmune disorders have been increasingly related to 22q11.2DS, and new phenotypes are being incorporated in the clinical spectrum of this syndrome. In our study we found that Graves disease in association with 22q11.2DS was reported in only sixteen patients, and fifteen cases were described in the last 13 years. Based on the incidence and on the amplitude of this recognized spectrum, we reinforce the findings of literature that Graves disease should be included on the 22q11.2DS manifestations, which would lead us to seek it with 22q11.2 deletion patients.

Newborn screening programs: should 22q11 deletion syndrome be added?

The highly variable 22q11 deletion syndrome has been proposed for addition to newborn screening panels. A literature review investigated the incidence and prevalence, clinical features, and prognosis of 22q11 deletion syndrome and other issues related to newborn screening. Severe complications that could potentially be helped by screening include cardiac defects in 80% (with 20% having no outward signs to aid detection), hypocalcemia that can lead to seizures in 20% (though hypocalcemia is routinely investigated in sick newborns), and severe immune deficiency in <1% (which would be identified by some states' severe combined immunodeficiency screens). Other benefits that do not fit traditional goals of newborn screening include treatment for complications such as failure to thrive and developmental delay or preventing a "diagnostic odyssey." Although universal screening may prove the incidence to be >1:5000, undetected life-threatening effects occur in a minority of 22q11 deletion syndrome patients. Concerns include an untested screening technique, difficulty obtaining results in time for cardiac intervention, the chance of "vulnerable child syndrome" in mild cases, and possibly detecting congenital heart disease more efficiently by other means. Because addition of tests for highly variable conditions such as 22q11 deletion syndrome is likely to set a precedent for other syndromes, reevaluation of newborn screening criteria should be considered.

Two cases of 22q11.2 deletion syndrome with anorectal anomalies and growth retardation

Clinical features associated with the deletion of 22q11.2 are highly variable. Most are diagnosed by cardinal congenital heart disease or hypoparathyroidism. In cases without major features, an early accurate diagnosis of 22q11.2 deletion syndrome is difficult. Congenital anorectal malformations (ARM), which can be detected soon after birth, have been rarely reported in 22q11.2 deletion syndrome. We report two cases of 22q11.2 deletion syndrome with ARM who showed growth retardation. ARM was detected in both patients without congenital heart disease or hypoparathyroidism at early infancy and they were followed by pediatric surgeons. Later, failure to thrive or short stature became evident, and they consulted with pediatric endocrinologists who subsequently confirmed the diagnosis of 22q11.2 deletion by fluorescent in situ hybridization analysis. The combination of ARM and growth retardation may lead to an early diagnosis of 22q11.2 deletion syndrome.

Identification of two novel chromosome regions associated with isolated growth hormone deficiency

The goal of this study was to identify novel candidate genes that may cause or predispose to growth hormone (GH) deficiency. DNA samples from 45 individuals with isolated GH deficiency were assessed using oligonucleotide microarray comparative genomic hybridization. Five individuals with previously unreported copy number variants were identified. Two of the five individuals were hemizygous for regions already known to cause GH deficiency (chromosomes 22q11.21 and 15q26.3). The remaining three individuals had copy number changes involving two novel chromosome regions. One individual had a homozygous deletion of a 2.2 Mb region of 13q33.1 that contains a single gene: integrin, beta-like 1 (ITGBL1). The remaining two individuals had duplications of 4.7 Mb on chromosome 20q13.13. This region includes eight genes not previously identified as copy number variants. These genes are ARFGEF2, CSE1L, DDX27, ZNFX1, C20orf199, SNORD12, KCNB1, and PTGIS. Thus, further investigations into these potential candidate genes are necessary.

The morphology of the sella turcica in velocardiofacial syndrome suggests involvement of a neural crest developmental field

We described the morphology of the sella turcica in individuals with velocardiofacial syndrome (VCFS), also known as chromosome 22q11.2 deletion syndrome, and compared the morphology with that of a control group of individuals from the Oslo University Craniofacial Growth Archive. The aim was to measure the cranial base angles in individuals with VCFS and, if possible, to discover the developmental field that may be involved in the condition. The study included 33 patients with VCFS from the Copenhagen Cleft Palate Center, Denmark. The genotype was confirmed by fluorescence in situ hybridization. The morphology of the sella turcica was described and measurements of the cranial base angles were performed on lateral cephalometric radiographs. The VCFS individuals had larger deviations in the morphology of the sella turcica compared to individuals from the Oslo University Craniofacial Growth archive. The deviations were mostly in the posterior part of the dorsum sellae. Individuals with VCFS had increased cranial base angles. The results of this study combined with the information in the literature on the main defects in VCFS (palatal abnormalities, cardiac anomalies, thymic hypoplasia or aplasia, hypothyroidism, and posterior brain abnormality), suggest involvement of a specific developmental field.

CHARGE (coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies/deafness) syndrome and chromosome 22q11.2 deletion syndrome: a comparison of immunologic and nonimmunologic phenotypic features

OBJECTIVES

CHARGE (coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies/deafness) syndrome and chromosome 22q11.2 deletion syndrome are known to have significant clinical overlap including cardiac anomalies, ear abnormalities, hearing loss, developmental delay, renal abnormalities, and cleft palate. Immunodeficiency has been well documented in 22q11.2 deletion, but there has been limited recognition of this potentially serious complication in CHARGE syndrome. The goals of our study were to identify clinical features unique to CHARGE syndrome or 22q11.2 deletion and to describe the spectrum of immunodeficiency found in patients with CHARGE syndrome.

METHODS

This study included 25 children diagnosed with CHARGE syndrome with positive CHD7 mutations through the Children's Hospital of Philadelphia genetics program. Clinical features and laboratory findings were reviewed retrospectively. We compared our findings to data available for a large cohort of patients with 22q11.2 deletion syndrome followed in our clinical genetics program.

RESULTS

Features found more commonly in CHARGE syndrome included coloboma, choanal atresia, facial nerve palsy, tracheoesophageal fistula, and genital hypoplasia in boys. A high incidence of marked hypocalcemia was observed in our study group (72%). We found a spectrum of cell-mediated immunodeficiency in our study group, which ranged from lymphopenia (60%) to severe combined immunodeficiency (8%). Defects in humoral immunity were documented in 4 patients and included severe hypogammaglobulinemia with decreased T-cell numbers, transient hypogammaglobulinemia during infancy, and immunoglobulin A deficiency.

CONCLUSIONS

The presence of coloboma, choanal atresia, facial nerve palsy, tracheoesophageal fistula, or genital hypoplasia in boys should alert the clinician to the possibility of CHARGE syndrome rather than the 22q11.2 deletion. Molecular testing for CHD7 mutations may help to confirm the diagnosis. In this study, significant hypocalcemia and lymphopenia occurred more frequently in patients with CHARGE syndrome than in those with 22q11.2 deletion syndrome. Early inclusion of immunologists to the multidisciplinary care team (as with 22q11.2 deletion) may be of great benefit to affected patients.

Early thyroid development requires a Tbx1-Fgf8 pathway

The thyroid develops within the pharyngeal apparatus from endodermally-derived cells. The many derivatives of the pharyngeal apparatus develop at similar times and sometimes from common cell types, explaining why many syndromic disorders express multiple birth defects affecting different structures that share a common pharyngeal origin. Thus, different derivatives may share common genetic networks during their development. Tbx1, the major gene associated with DiGeorge syndrome, is a key player in the global development of the pharyngeal apparatus, being required for virtually all its derivatives, including the thyroid. Here we show that Tbx1 regulates the size of the early thyroid primordium through its expression in the adjacent mesoderm. Because Tbx1 regulates the expression of Fgf8 in the mesoderm, we postulated that Fgf8 mediates critical Tbx1-dependent interactions between mesodermal cells and endodermal thyrocyte progenitors. Indeed, conditional ablation of Fgf8 in Tbx1-expressing cells caused an early thyroid phenotype similar to that of Tbx1 mutant mice. In addition, expression of an Fgf8 cDNA in the Tbx1 domain rescued the early size defect of the thyroid primordium in Tbx1 mutants. Thus, we have established that a Tbx1->Fgf8 pathway in the pharyngeal mesoderm is a key size regulator of mammalian thyroid.

Constitutional growth delay pattern of growth in velo-cardio-facial syndrome: longitudinal follow up and final height of two cases

We report two patients with velo-cardio-facial syndrome (VCFS) who were admitted to our pediatric endocrinology clinic because of short stature and followed longitudinally until attainment of final height. Both patients followed a growth pattern consistent with constitutional delay of puberty with normal and near normal final height. Case 2 also had partial growth hormone (GH) deficiency and severe short stature (height SDS -3.4 SDS), but showed spontaneous catch-up and ended up with a final height of -2 SDS. These cases suggest that short stature in children with VCFS is due to a pattern of growth similar to that observed in constitutional delay of growth and puberty.

The evolutionary social brain: From genes to psychiatric conditions

The commentaries on our target article, “Psychosis and Autism as Diametrical Disorders of the Social Brain,” reflect the multidisciplinary yet highly fragmented state of current studies of human social cognition. Progress in our understanding of the human social brain must come from studies that integrate across diverse analytic levels, using conceptual frameworks grounded in evolutionary biology.

DiGeorge syndrome: new insights

Most patients with the clinical features of DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes share a common genetic cause, namely, a deletion of chromosome 22q11, and define the most common deletion syndrome known at this time. The clinical features of the 22q11 deletion syndrome are highly variable between individuals; some have subtle findings, whereas others are severely affected. The most common clinical features include specific types of congenital heart disease, hypocalcemia, immunodeficiency, facial dysmorphia, palate anomalies, velopharyngeal dysfunction, renal anomalies, and speech and feeding disorders as well as neurocognitive, behavioral, and psychiatric disorders. A significant number of patients with tetralogy of Fallot, truncus arteriosus, an interrupted aortic arch, isolated aortic arch anomalies, and perimembranous ventricular septal defects have a 22q11 deletion. Routine testing for a 22q11 deletion in this subset of patients should be considered to provide anticipatory medical intervention and appropriate family counseling.

Craniosynostosis: another feature of the 22q11.2 deletion syndrome

We report on the presence of craniosynostosis in four patients with the 22q11.2 deletion. In light of previous reports of the association, we propose that the occurrence is higher than the general population incidence. Therefore, we suggest that craniosynostosis should be considered a manifestation of the 22q11.2 deletion and conversely that the 22q11.2 deletion should be considered in the differential diagnosis of craniosynostosis.

Morphological appearance and chemical composition of enamel in primary teeth from patients with 22q11 deletion syndrome

Patients with 22q11 deletion syndrome have many and complex medical problems, including hypocalcemia and/or hypoparathyroidism. Odontological findings include enamel aberrations in both dentitions. In order to describe enamel morphology, chemical composition in primary teeth, and to investigate the relationship between medical history and morphological appearance, dental enamel was investigated in 38 exfoliated primary teeth from 15 children and adolescents. Morphology was studied by the use of a polarized light microscope, microradiography, scanning electron microscopy, X-ray microanalysis, and secondary ion mass spectrometry. The morphological findings were compared with medical history. The teeth showed, in principle, a normal morphological appearance with regard to prism structure. A high frequency of aberrations, such as hypomineralization, hypoplasia and extra incremental lines, were found. The majority of the aberrations were found around the neonatal line. There was a relationship between high numbers of medical problems in the patients and enamel deviations. The result supports the hypothesis of under-reporting of both hypocalcemia and hypoparathyroidism in patients with 22q11 deletion syndrome.

Endocrine manifestations of chromosome 22q11.2 microdeletion syndrome

BACKGROUND

Endocrine abnormalities, including hypocalcemia, thyroid dysfunction, and short stature, are associated with chromosome 22q11.2 microdeletion syndrome. This study was undertaken to examine the frequencies and clinical features of endocrine abnormalities in patients with 22q11.2 microdeletion syndrome.

METHODS

We analyzed 61 patients with 22q11.2 microdeletion syndrome diagnosed based on the verification of microdeletion by fluorescent in situ hybridization (FISH) using a probe of the DiGeorge syndrome critical region (TUPLE1) at 22q11.2 and a control probe, ARSA at 22q13. Serum total calcium, phosphorus, and intact parathyroid hormone (PTH) levels were measured, thyroid function test was performed, and serum IGF-1 and IGFBP-3 levels were also estimated. Height and weight of patients were compared with individual chronological ages.

RESULTS

Hypocalcemia was found in 20 patients (32.8%), and overt hypoparathyroidism in 8 (13.1%). Two patients (3.3%) showed autoimmune thyroid diseases, 1 each with Graves' disease and Hashimoto thyroiditis. Ten patients (16.4%) were below the third percentile in height, but the serum IGF-1 level was normal in 9 out of these 10 patients.

CONCLUSION

Our findings show that patients with chromosome 22q11.2 microdeletion syndrome present with variable endocrine manifestations and variable clinical phenotypes. In addition to FISH analysis, careful endocrine evaluations are required in patients with this microdeletion syndrome, particularly for those with hypoparathyroidism or thyroid dysfunction.

The 22q11.2 deletion in African-American patients: an underdiagnosed population?

Findings associated with the 22q11.2 deletion often include congenital heart malformations, palatal anomalies, immunodeficiency, hypocalcemia, and developmental delay or learning disabilities. Often the clinical suspicion of the diagnosis in a patient with one or more of these findings is heightened based on the presence of a characteristic facial appearance. In our large cohort of 370 patients with the 22q11.2 deletion, we report the under-representation of African-Americans in our group, as well as, the paucity of craniofacial dysmorphism in these patients. We note that the absence of the typical facial features may result in decreased ascertainment in this population and, furthermore, may delay the implementation of palliative care, cognitive remediation, and recurrence risk counseling. We, therefore, suggest that the clinician's threshold of suspicion should be lower in African-American patients.

Das 22q11.2-Deletionssyndrom und seine Relevanz für die Kinder- und Jugendpsychiatrie

Zusammenfassung: Das 22q11.2-Deletionssyndrom ist das häufigste bekannte Mikrodeletionssyndrom beim Menschen. Betroffene Patienten können eine Vielzahl körperlicher Störungen zeigen, vor allem charakteristische dysmorphe Gesichtszüge, Herzfehler, Thymus- sowie strukturelle oder funktionelle Gaumenanomalien. Typisch sind auch deutliche Beeinträchtigungen der motorischen, sprachlichen, kognitiven und sozialen Entwicklung sowie psychiatrische Störungen. Nach dem aktuellen Forschungsstand treten bei Kindern und Jugendlichen mit einer Deletion 22q11.2 insbesondere Aktivitäts- und Aufmerksamkeitsstörungen, affektive Störungen sowie tiefgreifende Entwicklungsstörungen gehäuft auf. 2% aller schizophrenen Erkrankungen im Erwachsenenalter sollen durch eine Deletion 22q11.2 verursacht sein. Der Artikel gibt einen aktuellen Überblick über Ätiologie, körperliche Symptomatik, Entwicklungsaspekte und psychiatrische Komorbidität des 22q11.2-Deletionssyndroms. Es werden klinische Kriterien für die humangenetische Abklärung einer Deletion 22q11.2 bei Kindern und Jugendlichen mit psychiatrischen Störungen definiert. Außerdem werden Behandlungsmöglichkeiten für die beim 22q11.2-Deletionssyndrom häufigen psychiatrischen Störungen erörtert. Insgesamt wird bei psychisch kranken Kindern und Jugendlichen eine Deletion 22q11.2 bisher noch zu selten diagnostiziert - trotz ihrer klinischen Relevanz.

Parathyroid function and growth in 22q11.2 deletion syndrome

OBJECTIVE

To determine the frequency and expression of hypoparathyroidism and the factors of short stature in 22q11.2 deletion syndrome to optimize clinical care.

STUDY DESIGN

Cross-sectional study of 39 patients 9.7 +/- 0.8 (2.5-20) years of age.

RESULTS

The congenital abnormalities were cardiac defects in 33 of 39, thymus hypoplasia in 15 of 18 evaluated, and craniofacial dysmorphy in all; 15 patients (39%) had had one or more seizures. Before evaluation, 12 patients were hypocalcemic, with (n = 4) or without clinical manifestations, diagnosed before 1 month in 10 cases, at 3 months or 12 years in two others. At evaluation, 9 patients were hypocalcemic, 5 of 9 had been hypocalcemic, and 8 others had parathyroid hormone (PTH) concentrations low for their ionized calcium. One had high PTH without hypocalcemia and 2 were hypercalcemic. The values were below -2 SD at birth for weight and/or height in 26% of cases and at evaluation for height and body mass index in 23% and for insulin-like growth factor-I in 37%.

CONCLUSIONS

Parathyroid function was abnormal in 27 of 39 (69%) patients. This was not diagnosed in the majority. Short stature was probably due to intrauterine growth restriction, underweight, and growth hormone deficiency, as suggested by low insulin-like growth factor I.

Apparently unrelated cytogenetic abnormalities among 462 probands referred for the detection of del(22q) by FISH

Laboratory-based reports of the cytogenetic abnormalities detected during the course of testing for deletion del(22q) are scant. We report our findings from the testing with FISH of 462 patients suspected to have del(22q) between 1994 and 2000. Of these, 447 had a normal karyotype. An apparently unrelated cytogenetic abnormality was detected in 15 (3.2%). Two of these abnormalities involved reciprocal translocation with chromosome 22q and one of these showed del(22q) with FISH. The other abnormalities included sex chromosome aneuploidies and unbalanced rearrangements of various chromosomal segments. There was no commonality among these abnormalities and no correlation with other reported cases. Among those with a normal karyotype, an unexpected deletion of the control arylsulphatase A (ARSA) probe was found, providing a definite frequency of 1/262 for ARSA deletions among patients suspected to have del(22q). Of the 462 referrals, 48 (10%) had one or more additional diagnoses, and in this group, 4 (8%) had del(22q) and 2 (4%) had an apparently unrelated cytogenetic abnormality. The data highlight the importance of initial cytogenetic analysis in patients suspected of del(22q) and negates the use of interphase FISH screening by itself for del(22q). The finding of 3.2% unrelated cytogenetic abnormalities is noteworthy. FISH should be used in any structural rearrangement to ascertain if the relevant locus is deleted or not. The continued reporting of patients diagnosed with del(22q) found to have an unrelated cytogenetic abnormality will expand the phenotypic spectrum and possible gene mapping may refine phenotypic specificity.

Auxological evaluation in patients with DiGeorge/velocardiofacial syndrome (deletion 22q11.2 syndrome)

PURPOSE

Patients with microdeletion of chromosome 22q11.2 (del22q11) were studied, in order to evaluate auxological parameters and to correlate growth patterns with the presence of main clinical characteristics of the syndrome.

METHODS

Between January 1995 and March 2000, auxological parameters (weight, height, head circumference, and bone age) of 73 patients with del22q11 were collected. Five subgroups of patients were distinguished: Group I (37 patients) included patients aged between 0.3 and 4 years, Group II (20 patients) included patients aged between 5 and 10 years, Group III (16 patients) included patients aged between 11 and 16.3 years. The presence or absence of some clinical features was correlated to growth patterns.

RESULTS

Weight: in Group I, 5 of 37 (13.5%) patients were below the 3rd percentile, 29 of 37 (78.3%) were below the mean percentile, none was overweight; in Group II, 13 of 20 (65%) patients were between the 10th and the 50th percentiles; in Group III, weight corresponded to the 97th percentile in 5 of 16 (31.2%) patients, and in 2/16 (12.5%) adolescents, the weight measurements were even above the 97th percentile. Height: short stature was detected in 7 of 73 (9.6%) of the total patients; the patients with short stature were all < 10 years old; the height was within the normal age in all adolescent patients. Head circumference: it was below the 3rd percentile in 7 of 73 (9.6%), between the 3rd and the 25th percentiles in 36 of 73 (49.3%) patients, between the 25th and the 75th percentiles in 20 of 73 (27.3%) patients, and between the 75th and the 97th percentiles in 10 of 73 (13.7%) patients. Bone age: mean +/- SD bone age was -0.25 +/- 0.78 years. Comparisons: the only statistically significant correlation was that between the presence of feeding difficulties and underweight.

CONCLUSION

Auxological parameters of children with del22q11 are characterized by: (1) weight deficiency in the first years of age, (2) weight normalization in the following years, (3) development of obesity in adolescence, (4) short stature in 10% of the patients, (5) normal height in adolescents, (6) slight delay in bone age in infancy, (7) microcephaly in 10% of the patients.

Endocrine aspects of the 22q11.2 deletion syndrome

Hormonal disorders are common in patients with a 22q11.2 deletion. While hypoparathyroidism was the first endocrine disturbance documented in the DiGeorge syndrome, growth hormone deficiency, hypothyroidism, and hyperthyroidism are now known to occur in patients with a 22q11.2 deletion. This review briefly summarizes our current understanding of the spectrum of endocrinological manifestations of the 22q11.2 deletion and proposes guidelines for appropriate screening and management of endocrine disorders in patients with a 22q11.2 deletion.

Assessment of stature in children with orofacial clefting

PURPOSE

To assess stature in children with orofacial clefting to determine whether this population is at risk for short stature and if growth failure is caused by hypothalamic-pituitary dysfunction or if it is related to age, sex, or type of cleft.

DESIGN

Cross-sectional.

METHODS

All children 3 to 12 years old with nonsyndromic orofacial clefts who were evaluated as outpatients were measured; those who demonstrated growth failure were to have an evaluation of their hypothalamic-pituitary function. Data were also collected on sex, age, and type of cleft.

RESULTS

Children with orofacial clefting had significantly more growth failure than the general population (p < 0.005). The parents of four of the five children with growth failure refused further evaluation because "no one else was ever concerned about my child's height."

CLINICAL IMPLICATIONS

The high rate of growth failure in this population emphasizes the need for precise growth assessment of children with orofacial clefting. Growth failure should not be ignored or minimized in populations of children having other significant health care problems.