Atypical genitalia (i.e., a genital phenotype that is neither clearly male nor female) are caused by the atypical development of chromosomal, gonadal, or anatomical sex. The complex group of disorders that cause atypical genitalia are called differences of sex development (DSD).
DSD 可分为性染色体 DSD、46,XY DSD 或 46,XX DSD。
性染色体 DSD 源于非典型的性染色体组成，它包括特纳综合征（45,X，缺少一条性染色体）和 克兰费尔特综合征（XXY，具有一条额外的 X 染色体）等综合征。存在多种类型的染色体排列（例如 45,X/46,XY）时，就会出现嵌合体。
46,XX DSD are conditions characterised by excess exposure to androgens. Over 95% of causes of atypical genitalia with a 46,XX genotype are due to congenital adrenal hyperplasia secondary to 21 hydroxylase deficiency.
46,XY DSD 可能由多种病因造成，通常需要进行更加全面的诊断性评估。
The initial management of a neonate with atypical genitalia is a social and clinical emergency. The local team has a key role in coordinating the initial assessment and investigations, and supporting parents. It is important there is early discussion with a more specialist multidisciplinary team with expertise in paediatric endocrinology, genetics, and surgery, and with appropriate psychiatric/psychological support. For many DSDs, long-term surgical and psychosexual outcomes remain uncertain.
Differences of sex development (DSD) are congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. A subset of children with DSD present at birth with atypical genitalia (i.e., a genital phenotype that is neither clearly male nor clearly female) and without other dysmorphic features. Many causes have a genetic basis. A very rare exception may occur when there is virilisation of a 46,XX fetus by maternal virilising tumours or maternal exposure to androgenic drugs.
This topic addresses the initial approach to neonates with atypical genitalia who are not identified as having a specific chromosomal syndrome in which atypical genitalia may be one of a number of presenting features.
- atypical genitalia with no palpable gonads
- atypical genitalia with one palpable gonad
- atypical genitalia with bilaterally palpable gonads
- 表型为男性的患者阴茎长度小于 2.5 cm
- 表型为女性者的阴蒂长度大于1 cm
- 血清 17 羟孕酮
- 血清 11 去氧皮质醇和 11 去氧皮质酮
- 血清 LH 和卵泡刺激素 (FSH)
- 促肾上腺皮质激素 (ACTH) 刺激试验
- 人绒毛膜促性腺激素 (hCG) 刺激试验
- 苗勒管抑制物质 (MIS) 或抗苗勒管激素 (AMH)
all neonates presenting with atypical genitalia
46,XX：继发于 21 羟化酶缺乏症的先天性肾上腺皮质增生症（就诊时）
46,XX：继发于 21 羟化酶缺乏症的先天性肾上腺皮质增生症（性别决定后）
45, X/46, XY 混合型性腺发育不全
Justin H Davies, MD, FRCPCH, MRCP
Consultant Paediatric Endocrinologist
Honorary Senior Lecturer
University of Southampton
JD is chair of the British Society for Paediatric Endocrinology and Diabetes and a medical advisor to the Child Growth Foundation. He has received a travel bursary from Novo Nordisk and grants from the European Society for Paediatric Endocrinology and the Child Growth Foundation.
Gemma Watts, BMS, MRCPCH
Specialist Registrar in Paediatric Endocrinology
Department of Paediatrics
University Hospitals Southampton NHS Trust
GW declares that she has no competing interests.
Dr Justin Davies and Dr Gemma Watts would like to gratefully acknowledge Dr Ingrid A. Holm, a previous contributor to this topic. IAH declares that she has no competing interests.
Paul Saenger, MD, MACE
Professor of Pediatrics
Department of Pediatrics (Endocrinology)
Montefiore Medical Center
Albert Einstein College of Medicine
PS declares that he has no competing interests.
Mary M. Lee, MD
Professor of Pediatrics and Cell Biology
Vice-Chair of Academic Affairs in Pediatrics
Pediatric Endocrine Division
UMass Medical School
MML declares that she has no competing interests.
Patricia Y. Fechner, MD
Associate Professor Pediatrics
University of WA
Medical Director of DSD Program
Seattle Children’s Hospital
PYF declares that she has no competing interests.