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Short Stature Department of Pediatrics Soochow University Affiliated Children’s Hospital Short stature Aim and claim Understanding the growth of infant and child Familiar with the causes of short stature (mainly get hold of the causes of endocrine disorders) Get hold of the examination and investigation of short stature Short Stature As growth is the essential biological characteristic of childhood,failure of physical growth may be an important sign of disease. Short stature occurs in several endocrine diseases as the hormones from the pituitary(垂体),thyroid(甲状 腺),adrenals(肾上腺) and gonads(性腺) are involved in growth. Other types of disease in childhood can also impair growth and so the differential diagnosis of the short child is wide Short Stature There is a rapidly decelerating growth phase in infancy dependent on nutrition The steady,slowly decelerating growth phase in childhood is dependent on growth hormone The rapidly accelerating and decelerating pubertal growth spurt is dependent upon the normal secretion of GH(生长激素) and sex steroids(性类固醇激素). Definitions Any child whose height falls below the 3rd centile for his or her community should be considered short. The mean heights of children vary with race,geography and time. Causes of short stature *Familial short stature(家族性矮小) *Constitutional delay of pubertal growth spurt(体质性青春期延 迟) *lowbirth weight (低出生体重儿); malnutrition *Endocrine disorders: A.growth hormone deficiency(GHD) B .hypopituitarism C.hypothyroidism D.Cushing syndrome *Chromosomal disorders/syndrome: A.Turner syndrome B.Silver-Russell syndrome *Skeletal dysplasias: achondroplasia(软骨发育不良) *Emotional/psychosocial deprivation dwarfism(情感剥夺 性侏儒) *Chronic illness: A.congenital heart disease B.cystic fibrosis(囊性纤维化) C.cerebral palsy D.chronic renal failure Familial short stature A deceleration in linear growth to reach their target percentile which is determined largely by genetic factors Born with normal weight and length The height percentile is maintained,and final height is short but appropriate for the family Skeletal maturation and timing of puberty are normal Constitutional growth delay Growth pattern similar to those with familial short stature Have a delay in skeletal maturation and onset of puberty Pubertal catch-up growth Growth continues beyond the time the average child has stopped growing Final height is normal Lowbirth weight(IUGR) Intrauterine growth retardation Secondary to poor maternal environment ,fetal malnutrition,congenital infection etc Many children with IUGR exhibit catch-up growth during first 2-3 years of life 15%-20% will remain short through life Growth hormone deficiency(GHD) GH is produced by the anterior pituitary gland under the stimulation of GHRH and GHRIH GH is secreted in a pulsatile pattern in response to sleep,exercise,and hypoglycemia etc Growth hormone deficiency (GHD) Clinical feature Decreased growth velocity Delay in skeletal maturation and subnomal GH secretion Maybe isolated or with other pituitary hormone deficiencies hypothalamus- pituitary- gland axis (H-P-G 轴) hypothalamus- pituitary- gland axis hypothalamus- pituitary- gland axis (H-P-G轴) The pituitary gland is the major regulator of an elaborate hormonal system. The pituitary gland receives signals from the hypothalamus and responds by sending pituitary hormones to target glands. The target glands produce hormones that provide negative feedback at the level of the hypothalamus and pituitary. This feedback mechanism enables the pituitary to regulate the amount of hormone released into the bloodstream by the target glands . The pituitary's central role in this hormonal system and its ability to interpret and respond to a variety of signals have led to its designation as the "master gland." hypothalamus- pituitary- gland axis (H-P-G轴) The pituitary gland is composed of an anterior adenohypophysis(腺垂体前叶) and a posterior neurohypophysis(神经垂体) lobe. The anterior lobe constitutes about 80% of the gland. hypothalamus- pituitary- gland axis (H-P-G轴) A series of sequentially expressed transcriptional activation factors directs the differentiation and proliferation of anterior pituitary cell types, These proteins are members of large family of DNA-binding proteins resembling homeobox genes. The consequences of mutations in several of these genes are evident in human forms of multiple pituitary hormone deficiency. hypothalamus- pituitary- gland axis (H-P-G轴) Five cell types in the anterior pituitary produce 6 peptide hormones. So matotropes produce growth hormone (GH); lactotropes produce prolactin (PRL); thyrotropes make thyroid stimulating hormone (TSH); corticortropes express pro-opiomelanocortin (POMC), the precursor of adrenocprticotropic hormone (ACTH), and gonadotropes express both luteinizing hormone (LH) and follicle-stimulating hormone (FSH). GHD GHD may be congenital, genetic(gene mutation), or acquired (histiocytosis, cranial irradiation) Idiopathic GHD and GH insensitivity syndrome(mutation in the GH receptor) Infants GHD are of normal birth weight,slightly reduced in length Excess truncal adiposity Growth hormone deficiency Patients who are significantly short or are growing slowly,in whom GH insufficiency is considered. If the preliminary GH level is low ,formal provocative testing by insulin-induced hypoglycaemia,L-dopa or clonidine or more complex is indicated so that patients with classical severe GH deficiency may be identified. Growth hormone deficiency Clinical – especially if other pituitary deficiencies present Genetic testing Biochemical Peak GH to provocation. Remains controversial because of limitations with ‘normal’ data, reproducibilty, assay standardisation, primed vs non primed in peripubertal yrs Severe GHD <4-5 ug/L, Partial <7.5-10 ug/L Low IGF-I/IGF BP3. Require good reference ranges Imaging MRI Bone Age Hypothyroidism Thyroid hormone(T3.T4) play an important role in growth and nerve system development,the clinical features include: Deformity Short Mental defeciency or badly intellect Myxedema face(黏液性水肿面容) Steroid excess Steroid and GH is opposite or confrontation, So thesteroid excess may lead to GH low Clinical feature Fat , short, hair excess, moonshaped face, skin purple striae(皮肤紫纹) Short stature associated with syndromes Turner Syn.(chromosomal express 45XO) With micrognathia , cubitus valgus,(肘外翻) webbed neck,(颈蹼)low posterior hairline,edema of hands and feet,multiple pigmented nevi (多痣)etc Short may has the only clinical menifestation Uterus and ovary dysplasia GH can not be low Short stature associated with Syn. Silver-Russell Syn.express: Fat Short small eye fram, low intelligence disturbance of reproduction function Disproportionate short stature Skeletal dysplasia(achondroplasia)(软骨发 育不良) Measurements of arm span and upper-tolower body segment ratio are helpful to determine weather a child has normal body proportions Specific radiographic features It is rare Psychosocial short stature Emotional deprivation Fell depressing Often occurs in the misfortune family or be maltreated(abused) GH secretion diminished Foster home placement or a change in the phychosocial environment at home may improve growth Chronic illness Congenital heart disease Cystic fibrosis Cerebral palsy Chronic renal failure Diagnosis of short stature History Examination 1.Pragnancy and birth-low birth weight? 1.Height(centile chart) 2.Parental height-TCR 2.Growth(to monitor the velocity) 3.Family history-inherited diseases 3.Dysmophic features 4.the age of pubertal onset(skeletal closed?) 5.chronic illness?nutritional assessment 4.Weight(malnutrition) 5.Visual fields and sight (tumor exist?) 6.Stage of puberty(pubertal delay?) Diagnosis of short stature Investigations radiograph of left hand for bone age Karyotype (grasp chromosomal disorder) Skeletal survey Endocrine investigations(T3`T4`TSH; GH provocation test) Skull X-ray or CT and MRI(find out tumor) The management of short stature The treatment of short stature should be in view of the reason Familial short is not good method Constitutional delay of puberty can wait until his pubertal growth spurt is coming Lowbirth weight without catch-up growth can use HGH Chromosomal disorders are not effective methods except Turner Syn. Chronic illness needs to treat primary disorders The management of short stature Endocrine replacement treatment: Hypothyroidism needs to use thyroid hormone Cushing Syn. needs to treat primary disease GHD needs to endocrine replacement treatment The management of short stature Growth hormone dose:15 i.u ./m2/week mode of administration:daily,s.c.injections A child with congenital hypopituitarism treated from birth will grow quite normally.Children with GH insufficiency grow normally once introduced to treatment and show catch-up growth. Psychological treatment 思考题 Case : A boy 6 year old,chief complain is short ,no other signs and symtoms, the velocity of growth is below 4cm /yer,the birth weight is 3.5 Kg, the height is 100cm,the weight is 20Kg, he has normal body proportions,his father’s height is 172cm, his mother’s height is 160cm. The question is : how we diagnosis it? What should we do in order to help us make a diagnosis? The answer is: first we should confirm weather he is short according to the standard, then we should take some investagations, for example, radiograph of left hand for bone age; GH provocation test and skull MRI,we must take examination datial for his body in order to exclude other chronic illness, finaly ,we can make a diagnosis. 参考书目 《Paediatrics》 (mosby’s crash course) 科学出版社 《Paediatrics》 北京大学医学部出版社 谢 谢