Paediatrics Flashcards
Turner syndrome definition
Turner syndrome occurs when a female has a single X chromosome (45XO)
Turner syndrome presentation
Short stature
Webbed neck
High arched palate
Downward sloping eyes with ptosis
Broad chest with widely spaced nipples
Cubitus valgus (when the arm is extended downwards with the palms facing forward, the angle of the forearm at the elbow is exaggerated, angled away from the body)
underdeveloped ovaries
Late/incomplete puberty
Infertility
Turner syndrome complications
Recurrent UTIs
Recurrent otitis media
Coarctation of aorta
Bicuspid aortic valve
Hypothyroidism
Hypertension
Obesity
Diabetes
Osteoporosis
Learning disabilities
Turner syndrome management
Growth hormone therapy - prevent short stature
Oestrogen and progesterone replacement for female secondary sex characteristics
Fertility treatment
Klinefelter syndrome definition
Male with an additional X chromosome (47 XXY)
Rarely, can present with further X chromosomes e.g. 48 XXXY or 49 XXXXY
Klinefelter syndrome presentation
Usually appear normal till puberty
Taller height
Wider hips
Gynaecomastia (developing breasts)
Weaker muscles
Small testicles
Reduced libido
Shyness
Infertility
Subtle learning difficulties
Klinefelter syndrome management
Testosterone injections for symptomatic relief
Advanced IVF to aid fertility
Breast reduction
Speech and language therapy
Physiotherapy
Educational support
Klinefelter’s complications
Increased risk of
Breast cancer (less than women, more than XY men)
Osteoporosis
Diabetes
Anxiety & depression
Down’s, Edward’s & Patau syndromes definition
Down’s = trisomy 21
Patau = trisomy 13
Edward’s = trisomy 18
Down’s syndrome presentation
Hypotonia
Brachycephaly (small head with flat back)
Short neck
Short stature
Flattened face & nose
Prominent epicanthic folds
Upwards sloping palpebral fissures (gaps between lower and upper eyelid)
Single palmar crease
Down’s syndrome complications
Learning disability
Recurrent otitis media
deafness
Visual problems
Hypothyroidism
Cardiac defects
Atlantoaxial instability
Leukaemia more common in children
Dementia more common in adults
Down’s sydrome screening
11-14 weeks: combined test (nuchal translucency [>6mm], beta-HCG [high], PAPPA [low])
14-20 weeks: triple (beta-HCG [high], AFP [low] and serum oestriol [low]) or quadruple (same as triple plus inhibin A [high])
Antenatal testing for Down’s syndrome
Chorionic villus sampling (<15 weeks) - ultrasound guided biopsy of placental tissue
Amniocentesis (later in pregnancy) - ultrasound guided aspiration of amniotic fluid
Robertsonian translocation definition
Translocation (portion of one chromosome directly swapped with another) in acrocentric chromosomes (13, 14, 15, 21, 22). They have a long and short arm, and lose the short arm completely, with the two long arms joining
They are usually phenotypically normal but have 45 chromosomes and risk issues in their offspring
Congenital adrenal hyperplasia definition
Group of inherited genetic disorders (autosomal recessive) caused by enzyme deficiencies in the adrenal cortex, disrupting steroid hormone synthesis
Most common variant is 21-hydroxylase deficiency
Congenital adrenal hyperplasia presentation
Varies greatly depending on type and severity of enzyme defect
Typical features:
Ambiguous genitalia (esp in females due to in utero exposure to excessive androgens)
Hypotension
Salt wasting crises (low Na, high K, dehydration, shock & metabolic acidosis)
Vomiting
Virilisation (developing male secondary sexual characteristics)
Precocious puberty (males)
Congenital adrenal hyperplasia investigations
Blood test hormone assays - low cortisol and elevated 17-hydroxyprogesterone suggest CAH
Genetic testing
Imaging
Congenital adrenal hyperplasia management
acute treatment e.g. fluid & sodium replacement and hydrocortisone
Long-term hydrocortisone/fludrocortisone as needed
Patient education
Surgical intervention
Androgen insensitivity syndome definition
Difference in sex development involving hormonal resistance androgen receptor dysfunction affecting biological men (XY)
Precocious puberty definition
Early onset puberty
<8yrs in girls and <9yrs in boys
First signs of pubertal maturation are breast budding in girl and testicular volume >4mm in boys
Usually idiopathic in girls and pathological in boys
Forms of precocious puberty
Gonadotropin dependent (central precocious puberty)
Gonadotrophin independent (peripheral or pseudo precocious puberty)
Abnormal pattern of gonadotrophin secretion (variants of early sexual maturation)
Causes of central precocious puberty
Brain tumours (e.g. gliomas, germ cell tumours secreting HCG)
Hypothalamic hamartomas
Neurosurgery
Head injuries
Radiation therapy
Previous meningitis
Abscess
Congenital abnormalities
Causes of gonadotrophin independent/non-central precocious puberty
Congenital adrenal hyperplasia
McCune Albright syndrome
HCG secreting tumours
Adrenal, ovarian, testicular cancers
Aromatase excess syndromes
Exposure to exogenous sex steroid hormones
McCune Albright syndrome definition and presentation
GNAS gene mutation
Polyostotic fibrous dysplasia
Cafe-au-lait skin pigmentation
Autonomous endocrine hyperfunction
Delayed puberty definition and types
Onset of puberty >13yrs in girls and >14 years in boys
Constitutional delay (normal puberty just delayed)
Secondary
Hypogonadism (hypogonadotropic hypogonadism or hypergonadotropic hypogonadism)
Hypogonadism examples
Hypogonadotrophic hypogonadism:
Isolated gonadotrophin deficiency
Multiple pituitary hormone deficiency
Secondary to CNS tumours or cranial irradiation or congenital malformation
Hypergonadotrophic hypogonadism:
Turner’s Syndromes and Klinefelter’s
Idiopathic gonadal failure/ autoimmune
Secondary to TBI, Abdominal Dx and chemotherapy
Rare disorders e.g. FSH receptor mutations
Delayed puberty investigations
Clinical assessment of pubertal development
Hand-wrist x-ray to assess bone age
LH/FSH, thyroid hormones, oestrogen, testosterone
Hypogonadotropic hypogonadism definition/example
Low levels of gonadotrophins (LH/FSH) and sex hormones
e.g. Kallmann syndrome: X-linked recessive disorder, failure of GnRH-releasing neurons to migrate into the hypothalamus during development
Similar phenotype to Klinefelter’s but with a lack of colour vision and struggle with smell
Hypergonadotropic hypogonadism definition/example
High levels of gonadotrophins (LH/FSH) and low levels of sex hormones
e.g. Klinefelter’s, Turner’s syndrome
Prader-Willi syndrome definition
Genetic disorder resulting from genetic imprinting, particularly affecting a gene on chromosome 15 (15q11-q13 region)
The child only expresses the maternally inherited version of the gene
Prader-Willi syndrome presentation
Hypotonia
Poor feeding in infancy
Developmental delay
Short stature
Learning disabilities
Excessive hunger
Angelman syndrome definition
Genetic disorder resulting from genetic imprinting, particularly affecting a gene on chromosome 15 (15q11-q13 region)
The child only expresses the paternally inherited version of the gene
Angelman syndrome presentation
Fascination with water
Happy demeanour
Inappropriate laughter
Hand flapping
Epilepsy
ADHS
Wide mouth with widely spaced teeth
Severe delay/absence of speech development
Microcephaly
5a-reductase deficiency definition
Autosomal recessive genetic disorder affecting biological males in which 5a-reductase is defective or absent
Enzyme usually converts testosterone to dihydrotestosterone, a more potent form of the hormone
5a-reductase deficiency presentation/mechanism
5aR catalyzes the conversion of testosterone to DHT, which plays a key role in sexual differentiation of the genitalia and prostate during fetal development
Atypical genitalia
Hypospadias
Micropenis
Normal internal structures
Testes undescended
Androgen insensitivity syndrome definition
X linked disorder in which androgen receptor are dysfunctional (loss of function mutation), clinically significant only in XY males
Can be complete, presenting with female external genitalia, mild when the external genitalia are male, or partial, where the external genitalia are partially masculinised
Androgen insensitivity syndrome presentation
Internal, undescended testes (due to Y chromosome)
Short vagina or under-masculinised genitalia
Partial/complete regression of Mullerian structures
46XY karyotype
Normal or elevated testosterone, LH, and oestrogen
