Perimortem samples

Inborn errors of metabolism often present as acute life-threatening conditions, affecting one or more organs. Often the diagnosis is not established in life. As these disorders have genetic implications, it is imperative that an accurate diagnosis be made. This protocol has been designed to assist the diagnosis of patients suspected of having an inborn error of metabolism.

In each case samples of urine and blood should be collected. Sometimes CSF will be required, and for some disorders it is essential that other tissue samples (in particular liver and muscle in addition to skin) are collected. To maximise the chance of diagnosing inborn errors of metabolism tissue biopsies should be collected as soon as possible after death, preferably within 2 hours.

A member of the Genetic Metabolic Diseases Service at The Children's Hospital at Westmead is on call for any consultations relating to children with known or suspected inborn errors of metabolism, and can be contacted through the Hospital switchboard ([02] 9845 0000). In addition, the Histopathologist on call can be contacted on the same number for advice with regards to appropriate processing of tissue samples for histological or electron microscopy studies.

If the case might be a Coroner's Case, then no sample of any kind can be taken after death without the permission of the coroner. The coroner can be contacted at any time, through the metabolic physician on call at The Children's Hospital, Westmead, or through the Histopathologist.

Urine	10 mL (min 2 mL)	May often be obtained by direct bladder tap
		For amino acid profile, organic acid profile, acylglycines, orotic acid etc.
		Frozen or on ice. No added preservative.
Whole blood	10 mL	Critical Specimen that may be collected from the heart. For DNA studies EDTA (not lithium heparin). Can be stored at +4°C for 48 hours.
Dried blood spots	2 or 3 cards (that is 6 or 9 spots)	Dried blood spots are useful for DNA PCR techniques and are easy to store and transport in paper envelopes.
Plasma	3-4 mL (min 1 mL )	For free and acylcarnitine, quantitative amino acids, very long chain fatty acids, free fatty acids etc. Lithium Heparin (not EDTA). Contact your laboratory as the plasma needs to be separated within 20 minutes, then frozen at -80°C
CSF	1.0 mL (min 250 µL)	Only if readily available
		Must be free of red cells
		Freeze and store at -80°C
Skin	3x2 mm diameter (Full thickness sample)	May be obtained within 6 hours of death under sterile conditions
		Place in sterile tissue culture, or viral transport medium, or sterile normal saline, for temporary storage and transport
		Keep cool. Please do not freeze
		Send as soon as possible to a Cytogenetics Laboratory
Liver	Open Biopsy	Obtained within 2 hours of death, and sooner if possible. Before taking specimen check that a -70°C freezer (or dry ice) is available.
		Specimen obtained by needle biopsy perimortem, or direct removal of specimen of liver at open biopsy (preferable) immediately postmortem
		2 x 0.5 cm cubes. Wrap individually in foil and roll to exclude air
		Place foil parcels in plastic tube (urine container can be used temporarily).
		Store at -70°C and transport on dry ice (-80°C)
Muscle	Open Biopsy	Obtained within 2 hours of death and sooner if possible. Before taking specimen check that a 70°C freezer (or dry ice) is available.
	Open Biopsy	Essential if a mitochondrial respiratory chain defect is suspected
	Enzymology	2 x 0.5 cm cubes, wrapped in Alfoil, place in cryovial.
	Enzymology	Store at -70°C and transport on dry ice (-80°C)
	Histochemistry	Requires snap freezing (or dry ice)
	Histochemistry	Refer to specific instructions from Histopathologist or the CHW Metabolic Team
	Histology and Electron Microscopy	Requires 2 thin strips. Refer to specific instructions from Histopathologist
Photography & X-Rays		Can be done postmortem and are useful in selected cases.