Unexpected high frequency of skeletal dysplasia in idiopathic short stature and small for gestational age patients

Growth Hormone Treatment for Non-GHD Disorders: Excitement Tempered by Biology

The success of growth hormone (GH) replacement in children with classical GH deficiency has led to excitement that other causes of short stature may benefit similarly. However, clinical experience has shown less consistent and generally less dramatic effects on adult height, perhaps not surprising in light of increased understanding of GH and growth plate biology. Nonetheless, clinical demand for GH treatment continues to grow. Upon the 20th anniversary of the US Food and Drug Administration's approval of GH treatment for idiopathic short stature, this review will consider the factors underlying the expansion of GH treatment, the biological mechanisms of GH action, the non-GH-deficient uses of GH as a height-promoting agent, biological constraints to GH action, and future directions.

Exploring the Genetic Causes for Postnatal Growth Failure in Children Born Non-Small for Gestational Age

The most common causes of short stature (SS) in children are familial short stature (FSS) and idiopathic short stature (ISS). Recently, growth plate dysfunction has been recognized as the genetic cause of FSS or ISS. The aim of this study was to investigate monogenic growth failure in patients with ISS and FSS. Targeted exome sequencing was performed in patients categorized as ISS or FSS and the subsequent response to growth hormone (GH) therapy was analyzed. We found 17 genetic causes involving 12 genes (NPR2, IHH, BBS1, COL1A1, COL2A1, TRPS1, MASP1, SPRED1, PTPTN11, ADNP, NADSYN1, and CERT1) and 2 copy number variants. A genetic cause was found in 45.5% and 35.7% of patients with FSS and ISS, respectively. The genetic yield in patients with syndromic and non-syndromic SS was 90% and 23.1%, respectively. In the 11 genetically confirmed patients, a gain in height from -2.6 to -1.3 standard deviations after 2 years of GH treatment was found. The overall diagnostic yield in this study was 41.7%. We identified several genetic causes involving paracrine signaling, the extracellular matrix, and basic intracellular processes. Identification of the causative gene may provide prognostic evidence for the use of GH therapy in non-SGA children.

Spondyloenchondrodysplasia in five new patients: identification of three novel ACP5 variants with variable neurological presentations

Spondyloenchondrodysplasia (SPENCD) is an immune-osseous disorder caused by biallelic variants in ACP5 gene and is less commonly associated with neurological abnormalities such as global developmental delay, spasticity and seizures. Herein, we describe five new patients from four unrelated Egyptian families with complex clinical presentations including predominant neurological presentations masking the skeletal and immunological manifestations. All our patients had spasticity with variable associations of motor and mental delay or epilepsy. All except for one patient had bilateral calcification in the basal ganglia. One patient had an associated growth hormone deficiency with fair response to growth hormone therapy (GH) where the height improved from -3.0 SD before GH therapy to -2.35 SD at presentation. Patients had different forms of immune dysregulation. All patients except for one had either cellular immunodeficiency (3 patients) or combined immunodeficiency (1 patient). Whole exome sequencing was performed and revealed four ACP5 variants: c.629C > T (p.Ser210Phe), c.526C > T (p.Arg176Ter), c.742dupC (p.Gln248ProfsTer3) and c.775G > A (p.Gly259Arg). Of them, three variants were not described before. Our study reinforces the striking phenotypic variability associated with SPENCD and expands the mutational spectrum of this rare disorder. Further, it documents the positive response to growth hormone therapy in the studied patient.

International Consensus Guideline on Small for Gestational Age (SGA): Etiology and Management from Infancy to Early Adulthood

This International Consensus Guideline was developed by experts in the field of SGA of 10 pediatric endocrine societies worldwide. A consensus meeting was held and 1300 articles formed the basis for discussions. All experts voted about the strengths of the recommendations. The guideline gives new and clinically relevant insights into the etiology of short stature after SGA birth, including novel knowledge about (epi)genetic causes. Besides, it presents long-term consequences of SGA birth and new treatment options, including treatment with gonadotropin-releasing hormone agonist (GnRHa) in addition to growth hormone (GH) treatment, and the metabolic and cardiovascular health of young adults born SGA after cessation of childhood-GH-treatment in comparison with appropriate control groups. To diagnose SGA, accurate anthropometry and use of national growth charts are recommended. Follow-up in early life is warranted and neurodevelopment evaluation in those at risk. Excessive postnatal weight gain should be avoided, as this is associated with an unfavorable cardio-metabolic health profile in adulthood. Children born SGA with persistent short stature < -2.5 SDS at age 2 years or < -2 SDS at age of 3-4 years, should be referred for diagnostic work-up. In case of dysmorphic features, major malformations, microcephaly, developmental delay, intellectual disability and/or signs of skeletal dysplasia, genetic testing should be considered. Treatment with 0.033-0.067 mg GH/kg/day is recommended in case of persistent short stature at age of 3-4 years. Adding GnRHa treatment could be considered when short adult height is expected at pubertal onset. All young adults born SGA require counseling to adopt a healthy lifestyle.

Heterozygous NPR2 Variants in Idiopathic Short Stature

Heterozygous variants in the NPR2 gene, which encodes the B-type natriuretic peptide receptor (NPR-B), a regulator of skeletal growth, were reported in 2-6% cases of idiopathic short stature (ISS). Using next-generation sequencing (NGS), we aimed to assess the frequency of NPR2 variants in our study cohort consisting of 150 children and adolescents with ISS, describe the NPR2 phenotypic spectrum with a growth pattern including birth data, and study the response to growth hormone (GH) treatment. A total of ten heterozygous pathogenic/likely pathogenic NPR2 variants and two heterozygous NPR2 variants of uncertain significance were detected in twelve participants (frequency of causal variants: 10/150, 6.7%). During follow-up, the NPR2 individuals presented with a growth pattern varying from low-normal to significant short stature. A clinically relevant increase in BMI (a mean gain in the BMI SDS of +1.41), a characteristic previously not reported in NPR2 individuals, was observed. In total, 8.8% participants born small for their gestational age (SGA) carried the NPR2 causal variant. The response to GH treatment was variable (SDS height gain ranging from -0.01 to +0.74). According to the results, NPR2 variants present a frequent cause of ISS and familial short stature. Phenotyping variability in growth patterns and variable responses to GH treatment should be considered.

Exploring the genetic causes of isolated short stature. What has happened to idiopathic short stature?

Statural growth is underpinned by development of the growth plate during the process of endochondral ossification, which is strongly regulated by numerous local factors (intracellular, paracrine and extracellular matrix factors) and systemic factors (nutrition, hormones, proinflammatory cytokines and extracellular fluids). This explains why growth retardation can be associated with numerous pathologies, particularly genetic syndromes, hormonal or inflammatory conditions, or gastrointestinal disorders having a nutritional impact. However, in most cases (80%), no specific aetiology is found after clinical investigation and conventional additional tests have been carried out. In such cases, "idiopathic" short stature is diagnosed, which includes patients presenting with constitutional delay of growth and development and familial short stature, but also patients with very subtle constitutional skeletal dysplasia which are not easily identifiable. In recent years, new methods of genetic investigation (e.g. gene panels, exome or genome sequencing) have made it possible to identify many genetic variants associated with apparently isolated short stature. Indeed, it is still difficult to estimate the proportion of patients presenting with idiopathic short stature for which a molecular diagnosis of monogenic conditions could be made. This estimate varies hugely depending on the thoroughness of the clinical, laboratory and radiological assessments performed prior to molecular analysis, since retrospective analysis of positive cases usually reveals subtle signs of underlying syndromes or rare skeletal disorders. Molecular diagnosis in children is important to be able to offer genetic counselling and to organise patient management. Moreover, improved understanding of the molecular basis of these cases of short stature opens up numerous possibilities for more specific treatments targeting the growth plate. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Novel Physique Index for the Screening of Skeletal Dysplasia at Birth

This study aimed to devise a novel physique index and investigate its accuracy in identifying newborns with skeletal dysplasia in comparison with head circumference (HC)/height (HT) ratio. The birth weight (W), HT, and HC at birth of 1500 newborns were retrospectively collected. The linear regression equations and coefficients of determination (R²) were determined. The formulated equation was corrected by the mean weight for gestational age at birth (Wcorr) as a novel physique index for screening skeletal dysplasia. The index accuracy was assessed using receiver operating characteristic (ROC) curves in 11 newborns by fetal ultrasound and compared with that of the HC/HT ratio. The R² values between W and HT, (HT)², and (HT) ³ were 0.978, 0.990, and 0.993, respectively. Those between W and HC, (HC)², and (HC)³ were 0.974, 0.984, and 0.988, respectively. W/Wcorr × (HC/HT)³ was used as a novel physique index. Seven newborns had skeletal dysplasia. Our novel physique index had a higher area under the curve (AUC), sensitivity, and specificity than the HC/HT ratio (AUC: 1.00 vs. 0.86, sensitivity: 1.00 vs. 0.86, and specificity: 1.00 vs. 0.75, respectively). Our novel physique index was more accurate than HC/HT ratio and has the potential to accurately identify newborns with skeletal dysplasia.

Genetic Screening for Growth Hormone Therapy in Children Small for Gestational Age: So Much to Consider, Still Much to Discover

Children born small for gestational age (SGA), and failing to catch-up growth in their early years, are a heterogeneous group, comprising both known and undefined congenital disorders. Care for these children must encompass specific approaches to ensure optimal growth. The use of recombinant human growth hormone (rhGH) is an established therapy, which improves adult height in a proportion of these children, but not with uniform magnitude and not in all of them. This situation is complicated as the underlying cause of growth failure is often diagnosed during or even after rhGH treatment discontinuation with unknown consequences on adult height and long-term safety. This review focuses on the current evidence supporting potential benefits from early genetic screening in short SGA children. The pivotal role that a Next Generation Sequencing panel might play in helping diagnosis and discriminating good responders to rhGH from poor responders is discussed. Information stemming from genetic screening might allow the tailoring of therapy, as well as improving specific follow-up and management of family expectations, especially for those children with increased long-term risks. Finally, the role of national registries in collecting data from the genetic screening and clinical follow-up is considered.

An unusual diagnosis for an usual test

Background

Hereditary multiple osteochondromas (HMO) is a genetic condition characterized by the presence of multiple osteochondromas, usually at the lateral side of the most active growth plate of a long bone. These lesions may persist, be asymptomatic during childhood, and may increase in number and size until growth plates close. Therefore, diagnosis of HMO in children and young people can be challenging; while short stature can be more evident at the onset of puberty, asymptomatic ostheocondromas can progress into different degrees of orthopedic deformity. Moreover, multiple complications may arise due to the presence of osteochondromas, including tendon and compression muscle pain, neurovascular disorders, obstetric problems, scoliosis and malignant transformation into secondary peripheral chondrosarcoma in adulthood.

Case presentation

We report the case of a girl admitted to our Institute for growth delay. While laboratory tests, including growth hormone stimulation test, were normal, left hand X-ray revealed multiple osteochondromas, suggestive for HMO. The genetic test for EXT1 and EXT2 genes confirmed the radiological diagnosis, with a mutation inherited from the mother who displayed the same radiological abnormalities along with recurrent limb pain episodes.

Conclusions

HMO is a genetic condition whose diagnosis can be challenging, especially in females. Every pediatricians should consider a skeletal dysplasia in case of unexplained growth delay and a skeletal survey might be fundamental in reaching a diagnosis.

Sitting Height to Standing Height Ratio Reference Charts for Children in the United States

OBJECTIVE

To create reference charts for sitting height to standing height ratio (SitHt/Ht) for children in the US, and to describe the trajectory of SitHt/Ht during puberty.

STUDY DESIGN

This was a cross-sectional study using data from the 1988-1994 National Health and Nutrition Examination Survey III, a strategic random sample of the US population. Comparison between non-Hispanic White (NHW), non-Hispanic Black (NHB) and Mexican American groups was performed by ANOVA to determine if a single population reference chart could be used. ANOVA was used to compare SitHt/Ht in pre-, early, and late puberty.

RESULTS

NHANES III recorded sitting height and standing height measurements in 9569 children aged 2-18 years of NHW (n = 2715), NHB (n = 3336), and Mexican American (n = 3518) ancestry. NHB children had lower SitHt/Ht than NHW and Mexican American children throughout childhood (P < .001). In both sexes, the SitHt/Ht decreased from prepuberty to early puberty and increased in late puberty. Sex-specific percentile charts of SitHt/Ht vs age were generated for NHB and for NHW and Mexican American youth combined.

CONCLUSIONS

SitHt/Ht assessment can detect disproportionate short stature in children with skeletal dysplasia, but age-, sex-, and population-specific reference charts are required to interpret this measurement. NHB children in the US have significantly lower SitHt/Ht than other children, which adds complexity to interpretation. We recommend the use of standardized ancestry-specific reference charts in screening for skeletal dysplasias and have developed such charts in this study.

The Challenge of Defining and Investigating the Causes of Idiopathic Short Stature and Finding an Effective Therapy

Idiopathic short stature (ISS) comprises a wide range of conditions associated with short stature that elude the conventional diagnostic work-up and are often caused by still largely unknown genetic variants. In the last decade, the improvement of diagnostic techniques has led to the discovery of causal mutations in genes involved in the function of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis as well as in growth plate physiology. However, many cases of ISS remain idiopathic. In the future, the more frequent identification of the underlying causes will allow a better stratification of subjects and offer a tailored management. GH therapy has been proposed and approved in some countries for the treatment of children with ISS. To improve the efficacy of GH therapy, trials with GH combined with GnRH agonists, aromatase inhibitors, and even IGF-I have been conducted. This review aims to revise the current definition of ISS and discuss the management of children with ISS on the basis of the most recent evidence.

Towards a Rational and Efficient Diagnostic Approach in Children Referred for Growth Failure to the General Paediatrician

Based on a recent Dutch national guideline, we propose a structured stepwise diagnostic approach for children with growth failure (short stature and/or growth faltering), aiming at high sensitivity for pathologic causes at acceptable specificity. The first step is a detailed clinical assessment, aiming at obtaining relevant clinical clues from the medical history (including family history), physical examination (emphasising head circumference, body proportions and dysmorphic features) and assessment of the growth curve. The second step consists of screening: a radiograph of the hand and wrist (for bone age and assessment of anatomical abnormalities suggestive for a skeletal dysplasia) and laboratory tests aiming at detecting disorders that can present as isolated short stature (anaemia, growth hormone deficiency, hypothyroidism, coeliac disease, renal failure, metabolic bone diseases, renal tubular acidosis, inflammatory bowel disease, Turner syndrome [TS]). We advise molecular array analysis rather than conventional karyotyping for short girls because this detects not only TS but also copy number variants and uniparental isodisomy, increasing diagnostic yield at a lower cost. Third, in case of diagnostic clues for primary growth disorders, further specific testing for candidate genes or a hypothesis-free approach is indicated; suspicion of a secondary growth disorder warrants adequate further targeted testing.

Growth hormone therapy in children; research and practice - A review

Short stature remains the most common reason for referral to a pediatric Endocrinologist and its management remains a challenge. One of the main controversies is the diagnosis of idiopathic short stature and the role of new technologies for genetic investigation of children with inadequate growth. Complexities in management of children with short stature includes selection of who should receive interventions such as recombinant human growth hormone, and how should this agent dose be adjusted during treatment. Should anthropometrical data be the primary determinant or should biochemical and genetic data be used to improve growth response and safety? Furthermore, what is considered a suboptimal response to growth hormone therapy and how should this be managed? Treatment of children with short stature remains a "hot" topic and more data is needed in several areas. These issues are reviewed in this paper.

Children Born Small for Gestational Age: Differential Diagnosis, Molecular Genetic Evaluation, and Implications

Children born small for gestational age (SGA), defined as a birth weight and/or length below -2 SD score (SDS), comprise a heterogeneous group. The causes of SGA are multifactorial and include maternal lifestyle and obstetric factors, placental dysfunction, and numerous fetal (epi)genetic abnormalities. Short-term consequences of SGA include increased risks of hypothermia, polycythemia, and hypoglycemia. Although most SGA infants show catch-up growth by 2 years of age, ∼10% remain short. Short children born SGA are amenable to GH treatment, which increases their adult height by on average 1.25 SD. Add-on treatment with a gonadotropin-releasing hormone agonist may be considered in early pubertal children with an expected adult height below -2.5 SDS. A small birth size increases the risk of later neurodevelopmental problems and cardiometabolic diseases. GH treatment does not pose an additional risk.

A genetic approach to evaluation of short stature of undetermined cause

Short stature is a common presentation to paediatric endocrinologists. After exclusion of major endocrine or systemic disease, most children with short stature are diagnosed based on a description of their growth pattern and the height of their parents (eg, familial short stature). Height is a polygenic trait and genome-wide association studies have identified many of the associated genetic loci. Here we review the application of genetic studies, including copy number variant analysis, targeted gene panels, and whole-exome sequencing in children with idiopathic short stature. We estimate 25-40% of children diagnosed with idiopathic short stature could receive a molecular diagnosis using these technologies. A molecular diagnosis for short stature is important for affected individuals and their families and might inform treatment decisions surrounding use of growth hormone or insulin-like growth factor 1 therapy.

Skeletal Dysplasias: What Every Bone Health Clinician Needs to Know

PURPOSE OF REVIEW

This review highlights how skeletal dysplasias are diagnosed and how our understanding of some of these conditions has now translated to treatment options.

RECENT FINDINGS

The use of multigene panels, using next-generation sequence technology, has improved our ability to quickly identify the genetic etiology, which can impact management. There are successes with the use of growth hormone in individuals with SHOX deficiencies, asfotase alfa in hypophosphatasia, and some promising data for c-type natriuretic peptide for those with achondroplasia. One needs to consider that a patient with short stature has a skeletal dysplasia as options for management may be available.

Growth throughout childhood of children born growth restricted

OBJECTIVE

Many studies that examine growth in growth-restricted children at birth do not discriminate between fetal growth restriction (FGR) and small for gestational age (SGA). These terms however are not synonymous. In SGA, stunting and increased weight gain have been reported. We do not know if this holds true for FGR. Our aim was to study postnatal growth until age 12.5 years in a cohort of children born FGR due to early onset placental insufficiency, and its relation to FGR severity.

DESIGN

Prospective cohort study, follow-up of an antenatal randomised controlled trial in two tertiary centres.

PATIENTS

Children aged 12.5 years born after FGR, with mothers who had severe early onset hypertensive pregnancy disorders (N=96).

MAIN OUTCOME MEASURES

Anthropometry at age 12.5 years in SD scores (SDS).

RESULTS

Mean height SDS (SD) corrected for target height was -0.09 (0.94), mean body mass index (BMI) SDS was 0.00 (1.16) and mean head circumference SDS was -0.37 (1.11). Catch-up growth was at fastest rate between term age and 3 months and similar for height (0.55 SDS/months) and weight (0.49 SDS/months). Neither FGR severity nor gestational age was related to height and BMI at age 12.5 years.

CONCLUSIONS

Children born growth restricted due to early onset placental insufficiency have height and BMI scores comparable to their age-matched peers at age 12.5 years. FGR severity was not related to height and BMI at age 12.5 years. These reassuring results differ from most studies that examine SGA children.

[Characterization of patients with skeletal genetic diseases in a Colombian referral center]

INTRODUCTION

Short height in Colombia has an estimated prevalence of 10%. The 2009 Nosology and Classification of Skeletal Genetic Diseases described 456 clinical conditions using biochemical, molecular and radiological criteria for diagnosis.

OBJECTIVE

To analyze demographic, epidemiological and clinical variables in a group of patients with skeletal genetic diseases referred to the Instituto de Ortopedia Infantil Roosevelt.

MATERIALS AND METHODS

Patients referred between 2008 and 2014 were analyzed filtering 167 diagnoses of the International Classification of Diseases, 10th revision (ICD 10), related to skeletal genetic diseases. Demographic, epidemiological and clinical variables were explored using descriptive statistics. An intervention score was generated contemplating different combinations of treatments. An inferential statistical analysis using Student's t test was performed on such variables.

RESULTS

The most frequent reason for consultation was suspicion of a genetic skeletal disorder. The types of treatments considered included support, surgical, pharmacological and orthotics, and it was established that genetic skeletal disorders were associated with higher intervention scores while tall and short height showed a lower score.

CONCLUSIONS

Most referred patients were classified with genetic bone diseases, short stature and other monogenic genetic diseases. Significant differences were found between the age at symptoms onset and the age of diagnosis. Diversity was found in the therapeutic approach among different groups of pathologies. Patients with tall and short height showed lower intervention scores, which may warn on the need to reassess the therapeutic requirements of these groups.

Paleodysmorphology and paleoteratology: Diagnosing and interpreting congenital conditions of the skeleton in anthropological contexts

Most congenital conditions have low prevalence, but collectively they occur in a few percent of all live births. Congenital conditions are rarely encountered in anthropological studies, not least because many of them have no obvious effect on the skeleton. Here, we discuss two groups of congenital conditions that specifically affect the skeleton, either qualitatively or quantitatively. Skeletal dysplasias (osteochondrodysplasias) interfere with the histological formation, growth and maturation of skeletal tissues leading to diminished postural length, but the building plan of the body is unaffected. Well- known skeletal dysplasias represented in the archeological record include osteogenesis imperfecta and achondroplasia. Dysostoses, in contrast, interfere with the building plan of the body, leading to e.g. missing or extraskeletal elements, but the histology of the skeletal tissues is unaffected. Dysostoses can concern the extremities (e.g., oligodactyly and polydactyly), the vertebral column (e.g., homeotic and meristic anomalies), or the craniofacial region. Conditions pertaining to the cranial sutures, i.e., craniosynostoses, can be either skeletal dysplasias or dysostoses. Congenital conditions that are not harmful to the individual are known as anatomical variations, several of which have a high and population-specific prevalence that could potentially make them useful for determining ethnic origins. In individual cases, specific congenital conditions could be determinative in establishing identity, provided that ante-mortem registration of those conditions was ensured. Clin. Anat. 29:878-891, 2016. © 2016 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Anastrozole plus leuprorelin in early maturing girls with compromised growth: the "GAIL" study

PURPOSE

Aromatase inhibitors have been used to increase predicted adult height (PAH) in boys but in girls only in McCune-Albright syndrome. We investigated whether anastrozole combined with leuprorelin for up to 2 years is safe and effective in improving PAH in girls with early puberty and compromised growth, compared to leuprorelin alone.

METHODS

The "GAIL" study: girls treated with an aromatase inhibitor and an LHRH analogue, ISRCTN11469487, was a 7-year prospective phase IIa study with parallel design, performed at Athens Medical Center (C-A), and Attikon University Hospital, Athens, Greece (C-B). Forty girls, consecutively referred for early puberty (onset 7.5-9 years) with a PAH <-2 or >1.5 SD lower than their target height (TH), were included. Twenty started on leuprorelin sc/im 0.3 mg/kg/month plus anastrozole 1 mg/d p.o. (group-A, C-A) and 20 on leuprorelin (group-B, C-B) for 2 years or until the age of 10 years. Groups did not differ in age, height, BMI, bone age advancement (BAA), and distance of PAH from TH. Follow-up was at 6, 12, 18, and 24 m.

RESULTS

Reduction in BAA was significantly higher in group-A compared to group-B already by 6 m. Despite the transiently significant decrease in height velocity in group-A, gain in PAH SD was almost double by 12 and 18 m vs group-B and reached the maximum of +1.21 ± 0.45 (7.51 cm) vs +0.31 ± 0.37 (1.92 cm, p = 0.001) in group-B at 24 m. Group-A had no clinical or biochemical hyperandrogenism, unchanged normal bone density, and lumbar spine X-rays.

CONCLUSION

The co-administration of anastrozole with leuprorelin safely improves PAH in girls with compromised growth.

Severe Short Stature in Two Siblings as the Presenting Sign of ACP5 Deficiency

BACKGROUND

ACP5 deficiency is known to cause spondyloenchondrodysplasia (SPENCD), which is characterized by various autoimmune and neurological symptoms in addition to short stature.

METHODS

Two siblings from a consanguineous Turkish family, a girl aged 13 years (P1) and a boy aged 8 years (P2), presented to their endocrinologist with progressive growth failure and severe short stature (-5 SDS). They had no comorbid conditions and, on physical examination, there were no signs of an overt skeletal dysplasia with normal appearance of extremities. Other than a low baseline IGF-1, extensive laboratory workup, including growth hormone stimulation and IGF-1 generation tests, was normal. Exome sequencing was performed.

RESULTS

Exome sequencing identified the presence of a homozygous frameshift mutation (p.Ser258Trpfs*39) in ACP5 in both siblings, which was confirmed by Sanger sequencing. This specific mutation has previously been described in patients with SPENCD. Additional workup in the two siblings showed distinct features of skeletal dysplasia on X-rays consistent with SPENCD, but none of the common autoimmune or neurological abnormalities associated with this condition.

CONCLUSION

Severe short stature can be the only presenting sign of ACP5 deficiency and the latter could therefore be considered as a rare cause in the differential diagnosis of severe, proportionate growth failure.

Evaluation of the Child with Short Stature

Orthopedic surgeons frequently encounter short statured patients. A systematic approach is needed for proper evaluation of these children. The differential diagnosis includes both proportionate and disproportionate short stature types. A proper history and physical examination and judicious use of plain film radiography will establish the diagnosis in most cases. In addition to the orthopedic surgeon, most of these patients will also be evaluated by other specialists, including endocrinologists and geneticists. This article provides an overview of the evaluation of the child with short stature and offers several illustrative examples.

Growth and development. Bone dysplasia--a frequent cause of short stature in children

In children presenting with short stature, physicians often limit themselves to descriptive diagnoses such as idiopathic short stature or small for gestational age. Flechtner and colleagues now report a high frequency of bone dysplasias in these children, raising questions about the process of diagnosing short stature.