Tall Stature ✅ Flashcards
What is the most common cause of tall statue?
Familial tall stature
What does the increased likelihood that tall parents will produce tall children reflect?
The polygenetic inheritance of height
What should be considered when once parent is exceptionally tall?
The possibility of an autosomal dominant cause of tall stature
What management is required for familial tall stature?
Usually just explanation and reassurance
What management of familial tall stature can be used in rare circumstances?
- Suppression of final height by early induction of puberty
- Surgical epiphysiodesis to fuse the growth plates
How can early induction of puberty to suppress final height be achieved?
High dose oestrogen
How does early induction of puberty suppress final height?
It limits the pre-pubertal component of growth
Why has the use of early induction of puberty to suppress final height reduced?
Due to concerns about adverse longer term effects on fertility
What are the syndromic causes of tall statue?
- Marfan’s syndrome
- Sotos syndrome
- Beckwith-Wiedemann syndrome
What is the inheritance of Marfan’s syndrome?
Autosomal dominant
What is Marfan’s syndrome caused by?
Mutations in FBN1 gene
What does the FBN-1 gene encode?
The glycoprotein fibrillin-1
What does fibrillin-1 do?
Forms fibres in connective tissue
What are many of the features of Marfan’s syndrome linked o?
Connective tissue defects
What are the features of Marfan’s syndrome?
- Aortic root dilatation
- Mitral valve prolapse
- Ligmentous laxity
- Lens subluxation
- Scoliosis
- Striae
What monitoring is required in Marfan’s syndrome?
Long-term monitoring of cardiovascular status
What is Sotos syndrome caused by?
Mutations of NSD1 gene
What is Sotos syndrome associated with?
- Accelerated pre-natal and infantile growth
- Tall childhood stature
- Advanced bone age
- Variable degrees of learning difficulties
- Characteristic head shape
What is the result of Sotos syndrome being associated with an advanced bone age?
It leads to a normal adult height
What is the characteristic head shape in Sotos syndrome?
‘Pear shaped’ head with prominent forehead
What kind of disorder is Beckwith-Wiedemann syndrome?
Imprinting disorder
What genetic abnormality is Beckwith-Wiedemann syndrome associated with?
Defects in chromosome 11p15
Where can the defects in chromosome 11p15 come from in Beckwith-Wiedemann syndrome?
Uniparental disomy
What do the chromosomal abnormalities in Beckwith-Wiedemann syndrome lead to?
Overactivity of the gene that encodes the IGF-2 growth factor and absence of CDKN1C
What does CDKN1c encode?
Inhibitor of cell proliferation
What are the features of Beckwith-Wiedemann syndrome?
- Overgrowth
- Hemi-hypertrophy
- Defects in anterior abdominal wall
- Macroglossia
- Hypoglycaemia
- Abnormal ear creases
- Increased predisposition to tumours
Which tumour in particular is there an increased predisposition to in Beckwith– Wiedemann syndromee?
Wilm’s tumour
What are the endocrine causes of tall stature?
- Precocious puberty
- Thyrotoxisosis
- Familial glucocorticoid deficiency
- GH secreting tumours
What is the most common endocrine cause of tall stature?
Precocious puberty
What has demonstrated the importance of oestrogen action in stimulating the fusion of growth plates?
The observation that the two very rare conditions of aromatase deficiency and oestrogen receptor defects lead to extreme tall stature
