Cognitive and adaptive behavior profiles in Smith-Magenis syndrome

Smith-Magenis syndrome (SMS) is a multiple congenital anomalies and mental retardation syndrome associated with an interstitial deletion of chromosome 17 band p11.2. The incidence of this microdeletion syndrome is estimated to be 1 in 25,000 individuals. Persons with SMS have a distinctive neurobehavioral phenotype that is characterized by aggressive and self-injurious behaviors and significant sleep disturbances. From December 1990 through September 1999, 58 persons with SMS were enrolled in a 5-day multidisciplinary clinical protocol. Developmental assessments consisting of cognitive level and adaptive behavior were completed in 57 persons. Most patients functioned in the mild-to-moderate range of mental retardation. In addition, we report that patients with SMS have low adaptive functioning with relative strengths in socialization and relative weakness in daily living skills. These data were analyzed in light of the molecular extent of the microdeletion within 17p11.2. We found that the level of cognitive and adaptive functioning does depend on deletion size, and that a small percentage of SMS patients have cognitive function in the borderline range.     

Growth hormone neurosecretory dysfunction associated with ring chromosome 18

The patient was a girl 5 years and 1 month old of markedly short stature (–3.9 SD) for her chronological age. Although her karyotype was 46, XX, r(18)(p11q23), there were no symptoms of a chromosomal deletion. Other authors have described cases with a ring autosome showing a phenotype with short stature alone as ‘ring syndrome’, regardless of which autosome is involved. The present case seems to fall into this category. Although blood growth hormone (GH) showed normal responses to four types of provocative tests, the mean value of blood GH levels obtained at 30 min intervals for 24 h was low, indicating the existence of growth hormone neurosecretory dysfunction (GHND)     

Sensory Motor and Functional Skills of Dizygotic Twins: One with Smith–Magenis Syndrome and a Twin Control

Smith–Magenis syndrome (SMS), the result of an interstitial deletion within chromosome 17p11.2, is a disorder that may include minor dysmorphic features, brachydactyly, short stature, hypotonia, speech delays, cognitive deficits, signs of peripheral neuropathy, scoliosis, and neurobehavioral problems including sleep disturbances and maladaptive repetitive and self-injurious behaviors. Physical and occupational therapists provide services for children who have the syndrome, whose genetic disorder is frequently not identified or diagnosed before 1 year of age. A comprehensive physical and occupational therapy evaluation was completed in nonidentical twins with one having SMS, using the Sensory Profile; Brief Assessment of Motor Function (BAMF); Peabody Developmental Motor Scales, Second Edition (PDMS-2); and Pediatric Evaluation of Disability Inventory (PEDI). This provides a framework for conducting assessments to enhance early detection and interdisciplinary management with this specialized population.     

Le syndrome de Smith-Magenis

Smith-Magenis syndrome is caused by a 17p11.2 deletion. It associates mental retardation, facial dysmorphism and brachydactyly; aberrant behavior and major sleep problems are present in 70% of the cases. It is probably under-diagnosed because the facial abnormalities are mild and the behavioral problems with hyperactivity and self-injuries are dominant, leading to the diagnosis of psychiatric pathology. However these behavioral problems are sufficiently characterized to allow the diagnosis of the syndrome and look for a 17p11.2 microdeletion. Otorhinolaryngologic, ophtalmologic, cardiac and renal abnormalities can be associated and their evaluation is necessary. Smith-Magenis syndrome is considered as a contiguous gene syndrome. Genes have been mapped and isolated to the critical region, but their participation in the pathogenesis of the syndrome remains unclear.     

Diagnostic difficulties in Smith-Magenis Syndrome (SMS) on the basis of own experience and literature data

The Smith-Magenis syndrome (SMS) is a rare microdeletion dysmorphic syndrome (interstitial microdeletion of chromosome 17p11.2), which occurs sporadically. Mutations in the RAI1 gene are found in part of the patients. SMS is characterized by intellectual disability and behavioural disturbances (sleep disturbances, hyperactivity, attention deficit, self-injury behaviour), craniofacial dysmorphism and defects of other organs and systems (teeth, eyes and upper respiratory and hearing disturbances, short stature, brachydactyly, scoliosis, cardiac and genitourinary defects). There are also neurological problems (muscular hypotonia, peripheral neuropathy, epilepsy and decreased sensitivity to pain). Many of the features that appear in the SMS may occur in other genetic syndromes, which may cause diagnostic difficulties. We report two cases of late diagnosed patients with the Smith-Magenis syndrome. Additionally, we present a review of literature and differential diagnosis. This may help in making the diagnosis and in giving optimal medical and psychological care to patients with SMS.     

Smith-Magenis syndrome: case report and review

Smith-Magenis syndrome (SMS) is characterized by distinctive facial features that progress with age, developmental delay, cognitive impairment, and behavioral abnormalities associated with molecular anomaly in 17p11.2. Treatment includes: early childhood intervention programs, special education, vocational training later in life, and speech/language, physical, and occupational, behavioral, and sensory integration therapies. We report a 14-year-old girl with mental retardation, behavioral abnormalities and facial dysmorphism, with SMS diagnosis confirmed by cytogenetic analysis and in situ hydridization (FISH).     

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

The list of findings associated with the 22q11.2 deletion is quite long and varies from patient to patient. The hallmark features include: conoruncal cardiac anomalies, palatal defects, thymic aplasia or hypoplasia, T cell abnormalities, mild facial dysmorphia, and learning disabilities. The 22q11.2 deletion has been seen in association with the DiGeorge sequence, velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome, isolated conotruncal cardiac anomalies, and some cases of autosomal dominant Optiz G/BBB syndrome. Short stature has been seen in one to two thirds of children reported in the literature with a diagnosis of VCFS, but growth hormone deficiency (GHD) has not been described in conjunction with this diagnosis. We present 4 patients with a 22q11.2 deletion and short stature who were found to have abnormalities in the growth hormone-insulin-like growth factor I axis. All had growth factors less than -2 SD for age and failed provocative growth hormone testing. Two patients were found to have abnormal pituitary anatomy. In our population, the incidence of GHD in 4 or 95 children with 22q11 deletion is significantly greater than the estimated incidence of GHD in the general population. Children with a 22q11.2 deletion appear to be at a greater risk for pituitary abnormalities. Therefore, those children with the 22q11.2 deletion and short stature or poor growth should be evaluated for GHD, as replacement growth hormone therapy may improve their growth velocity and final height prediction.     

Growth hormone deficiency associated with 22q11.2 deletion: a case report

The 22q11.2 microdeletion produces many syndromes, characterized by similar phenotypical features. The most known syndromes are: the DiGeorge syndrome, the velocardiofacial syndrome, the conotruncal anomaly face syndrome. The hallmark features are represented by cardiac anomalies, palate defects, immune and cognitive deficiencies, facial dysmorphisms. Less common disorders include: genito-urinary abnormalities, visual defects, autoimmune disorders and pituitary anomalies, being the last represented by growth hormone and/or insulin growth factor-I deficiency. We present the case of a 8 years old male admitted to our Division for failure to thrive. We found growth hormone deficiency and pituitary hypoplasia associated with some of the anomalies shown above, thus we suspected and confirmed the 22q11.2 deletion syndrome. In literature few cases of associated 22q11.2 deletion syndrome with growth hormone deficiency are described, while short stature between children with and children without cleft palate is reported to be more frequent in the first ones, suggesting that the 22q11.2 deletion syndrome remains undetected in many affected children and that the growth hormone deficiency prevalence in affected children has to be investigated. The wide phenotypical presentation of 22q11.2 deletion syndrome requires a multidisciplinary approach to the affected subject and, from the auxologic point of view, is good to monitoring the growing trend and, if short stature is present, check for the growth hormone deficiency.     

Inversion of the circadian rhythm of melatonin in the Smith-Magenis syndrome.

OBJECTIVE: The objective was to determine the circadian rhythm of melatonin in the Smith-Magenis syndrome (SMS), which causes behavioral problems and sleep disturbance. STUDY DESIGN: Questionnaires, sleep consultations, and sleep diaries were obtained in 20 children with SMS (9 girls, 11 boys aged 4 to 17 years). Actigraphy, electroencephalography, and the circadian variations of plasma melatonin, cortisol, and growth hormone were recorded in 8 patients. Early sleep onset, early sleep offset, and sleep attack indicated sleep disturbance. RESULTS: All children with SMS had a phase shift of their circadian rhythm of melatonin. Time at onset of melatonin secretion was 6 AM +/- 2 (control group: 9 P.M. +/- 2). Peak time was 12 PM +/- 1 (control group: 3:30 AM +/- 1:30), and melatonin offset was at 8 PM +/- 1 (control group: 6 AM +/- 1). Behavioral problems correlated with the inverted circadian rhythm of melatonin. CONCLUSION: Considering that clock genes mediate the generation of circadian rhythms, we suggest that haploinsufficiency for a circadian system gene mapping to chromosome 17p11.2 may cause the inversion of the circadian rhythm of melatonin in SMS.     

Microarray analysis of unbalanced translocation in Wolf‐Hirschhorn syndrome

Wolf–Hirschhorn syndrome (WHS) is caused by deletions involving chromosome region 4p16.3, which is characterized by growth delay, mild‐to‐severe mental retardation, hypotonia, facial dysmorphisms and shows extensive phenotypic variability include feeding difficulties, epilepsy and congenital anomalies. Variation in the size of the deletion involving chromosome region 4p16.3 may explain the clinical variation. However, previous studies indicate that duplication for another chromosome region due to an unbalanced translocation elucidate approximately 40–45% WHS patients. Therefore, we used whole genomic cytogenetics array to analyze the entire genome at a significantly higher resolution over conventional cytogenetics to characterize the exact subtelomeric aberration region of one patient with developmental delay and several facial characteristics reminiscent Wolf–Hirschhorn syndrome. Here we report that our patient had 3.7 Mb deletion at the 4p16.2 and 6.8 Mb duplication at 8p23.1 resulted from the unbalanced translocations der(4)t(4;8)(p16.2;p23.1). We confirmed that our patient with monosomy 4p16.2 which is consistent with Wolf–Hirschhorn syndrome and trisomy 8p23.1. The combination of the 4p deletion with 8p partial trisomy explains the complex phenotype presented by our patient.     

Natural histories of patients with Wolf‐Hirschhorn syndrome derived from variable chromosomal abnormalities

Wolf‐Hirschhorn syndrome (WHS) is a subtelomeric deletion syndrome affecting the short arm of chromosome 4. The main clinical features are a typical craniofacial appearance, growth deficiency, developmental delays, and seizures. Previous genotype‐phenotype correlation analyses showed some candidate regions for each clinical finding. The WHS critical region has been narrowed into the region 2 Mb from the telomere, which includes LETM1 and WHSC1; however, this region is insufficient to cause “typical WHS facial appearance”. In this study, we identified 10 patients with a deletion involving 4p16.3. Five patients showed pure terminal deletions and three showed unbalanced translocations. The remaining patients showed an interstitial deletion and a suspected inverted‐duplication‐deletion. Among 10 patients, one patient did not show “typical WHS facial appearance” although his interstitial deletion included LETM1 and WHSC1. On the other hand, another patient exhibited “typical WHS facial appearance” although her small deletion did not include LETM1 and WHSC1. Instead, FGFRL1 was considered as the candidate for this finding. The largest deletion of 34.7 Mb was identified in a patient with the most severe phenotype of WHS.     

6p subtelomere deletion with congenital glaucoma,severe mental retardation,and growth impairment

Submicroscopic deletion of the 6p subtelomere has recently been recognized as a clinically identifiable syndrome. A distinct phenotype has emerged consisting of developmental delay/mental retardation, language impairment, hearing loss, and ophthalmologic, cardiac, and craniofacial abnormalities, including hypertelorism, midface hypoplasia, small nose, and high arched palate. We describe here a patient with 6p subtelomere deletion associated with congenital glaucoma, severe mental retardation, and growth impairment. Fluorescent in situ hybridization analysis revealed only one 6p25.3 signal. Array comparative genomic hybridization assay showed 2.1 Mb deletion and 4.14 Mb duplication in the 6p25 region. Generally, developmental delay and language impairment are common findings in patients with 6p subtelomere deletion syndrome, but growth impairment is not. Compared to that, the present patient showed atypically severe developmental delay and growth impairment.     

Kleinwuchs und Therapie

Short stature is a diagnostic challenge because of the enormous spectrum of physiological maturation and growth patterns in childhood. A carefully drawn growth chart and calculation of the familial target height are required for a correct analysis. A low growth velocity, a height below the familial target, severe short stature and disproportionate or syndromic short stature are rational reasons for referral to a growth specialist. For clinical assessment a small for gestational age (SGA) patient history, presence of minor or major anomalies and skeletal disproportions should guide the diagnostic approach. Bone age estimation may enable the differentiation between inborn (primary) and acquired (secondary) growth failure. Growth hormone (GH) stimulation tests should only be performed if GH deficiency is very likely based on the foregone diagnostics. Constitutional delay of growth and puberty should not be confused with GH deficiency. A GH therapy is effective in GH deficiency and allows a normal growth within the familial target range in the majority of treated children. In addition, the diagnosis and therapy of Turner syndrome, SGA short stature and short stature homeobox-containing gene (SHOX) deficiency are discussed.     

Growth hormone secretion in children and adolescents with familial tall stature

Sixty-five patients (22 boys and 43 girls) presenting with familial tall stature were investigated with regard to growth hormone (GH) secretion, both physiological and after stimulation with thyrotropin releasing hormone (TRH) and growth hormone relasing hormone (GHRH). Plasma insulin-like growth factor-I (IGF-I) was also measured. Two groups of patients were distinguished according to their physiological secretion of GH: a high secretory group (n=49) with a mean 24 h integrated concentration of GH (IC-GH) of 5.4±2.3 g/l per minute and a large number of peaks (5.1±1.6 in 24 h), and a low secretory group (n=16) with a mean 24 h IC-GH of 2.1±0.5 g/l per minute and few peaks (3.3±1.3 in 24h). Plasma IGF-I levels and GH peak values after the TRH test were significantly higher in the high secretory group. These results indicate that familial tall stature is the consequence either of hypersecretion of GH or of hypersensivity to this hormone (IGF-I levels being normal in spite of low GH levels).     

Physiological Growth Hormone Secretion and Response to Growth Hormone Treatment in Children with Short Stature and Intrauterine Growth Retardation

Stanhope, R., Ackland, F., Hamill, G., Clayton, J., Jones, J. and Preece, M.A. (Department of Growth and Development, Institute of Child Health, London and Serono Laboratories, UK). Physiological growth hormone secretion and response to growth hormone treatment in children with short stature and intrauterine growth retardation. Acta Paediatr Scand [Suppl] 349: 47, 1989.
Physiological growth hormone (GH) secretion was examined in 31 children (8 girls, 23 boys) with short stature secondary to intrauterine growth retardation (IUGR). Seventeen (4 girls, 13 boys) had dysmorphic features of Russell-Silver syndrome. Four of the 31 children had GH insufficiency with peak GH levels of < 20 mU/I during the night. Nine of the patients (8 of whom had Russell-Silver syndrome) had a single nocturnal GH pulse. Twenty-three children (6 girls, 17 boys) were randomized into two groups treated with either 15 or 30 U/m²/week of GH by daily subcutaneous injections. Age, sex distribution, pretreatment height velocity SD score (SDS), and distribution of dysmorphic and non-dysmorphic children were similar in both groups. The group treated with 15 U/m2/week for a mean of 0.82 years showed an increase in mean height velocity SDS from - 0.61 to +1.09, and the group treated with 30 U/m²/week for a mean of 0.92 years showed an increase in mean height velocity SDS from -0.69 to +3.48. The results suggest that physiological GH insufficiency is probably common in children with Russell-Silver syndrome and that both dysmorphic and non-dysmorphic children with short stature secondary to IUGR will respond to GH treatment. Initial evidence suggests that the increase in short-term growth velocity does not result in an improved final height prognosis.     

Correlation between pituitary growth hormone reserve and degree of growth failure in children with short stature

The correlation between a releasable pituitary growth hormone (GH) pool and degree of growth failure was examined in 30 children with GH deficiency (group I) and 19 children with normal short stature (group II). Based on the responsiveness of GH to GH-releasing hormone (GHRH), group I, with low GH responses (below 7 ng/ml) to both insulin and arginine, was classified into three subgroups; I_a (peak value less than 10 ng/ml, n=19), I_b (10–20 ng/ml, n=5) and I_c (above 20 ng/ml, n=6). Group II, with a GH response above 10 ng/ml to either insulin or arginine, was also divided into II_a (below 20 ng/ml, n=5) and II_b (above 20 ng/ml, n=14). Body length and growth velocity in I_a and I_b were significantly reduced vs I_c; bone age in I_a was retarded vs I_c; plasma somatomedin C (Sm-C) levels in I_a and I_b were decreased vs I_c, who had almost normal levels (0.90±0.55 U/ml). The incidence of other combined pituitary hormone deficiencies and previous perinatal distress was definitely high in I_a and I_b, but zero in I_c. In group II also, body length and growth velocity were significantly decreased in II_a vs II_b (P<0.01). These results indicate that [1] the pituitary reserve of GH estimated by GHRH is a good reflection of the degree of growth failure in GH-deficient children as well as in those of normal short stature, [2] hypothalamic GHRH deficiency tends to have a milder effect on growth retardation than pituitary GH deficiency, and [3] normal short children with a diminished GH reserve may be potential candidates for the GH treatment.Abbreviations ACTH adrenocorticotropin - LH luteinizing hormone - LH-RH luteinizing hormone-releasing hormone - GH growth hormone - GHRH growth hormone-releasing hormone - Sm-C somatomedin C - TRH thyrotropin-releasing hormone - TSH thyrotropin     

Growth hormone deficiency in Dubowitz syndrome

Severe short stature as a result of intra-uterine growth retardation is one of the characteristics of Dubowitz syndrome. There have been few reports elaborating growth hormone secretory status in this syndrome. A child with Dubowitz syndrome, who was found to have complete growth hormone (GH) deficiency and who responded to growth hormone therapy, is described. This appears to be the first documentation of GH deficiency in this syndrome.     

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.