Table 4.

The F9 mutational spectrum in Malaysian Haemophilia B (HB) patients. The summary of the genetic alterations in the F9 gene from our Malaysian HB patients. Nucleotide numbering (c.) is according to coding bases from A (nucleotide +1) the initiation methionine (ATG) at position −29 (F9 mRNA gene bank ref. NM_000133.3) and protein numbering (p.) follows amino acid sequences that assign the first residue Methionine as +1 in factor IX protein sequence (NP_000124.1) according to Human Genome Variation Society guidelines.²⁸

Patient	Ethnicity	F9 Exon	F9 domain	Nucleotide Changes	Amino Acid Changes	Novelty	Disease Severity	Mutation Effects
HB2	Malay	Intron2	-	c.253-17_253-13DelTCTTT	-	Novel	Severe	Acceptor splice site
HB4	Malay	7	Serine Protease	c.803G>A	p.C268Y	Novel	Severe	Missense
HB12	Indian	1	Signal Peptide	c.39DelC	p.L14Sfs*7	Novel	Moderate	Frameshift
HB13	Malay	1–4	Signal-Pro-peptide-GLA-EGF1	-	-	Novel	Severe	Large deletion
HB1	Indian	Intron2	-	c.252+1G>A	-	Reported	Severe	Donor splice site
HB3	Malay	8	Serine Protease	c.1237G>A	p.G413R	Reported	Severe	Missense
HB5	Malay	8	Serine Protease	c.1135C>T	p.R379*	Reported	Moderate	Nonsense
HB7/HB14	Malay/ Malay	2	Pro-peptide	c.128G>A	p.R43Q	Reported	Moderate/ Severe	Missense
HB8	Malay	Intron1	-	c.88+5G>C	-	Reported	Moderate	Donor splice site
HB9	Malay	7	Serine Protease	c.800A>G	p.H267R	Reported	Severe	Missense
HB10	Malay	5	EGF2	c.415G>A	p.G139S	Reported	Severe	Missense
HB11	Chinese	4	EGF1	c.383G>A	p.C128Y	Reported	Moderate	Missense
HB15	Malay	2	GLA	c.223C>T	p.R75*	Reported	Severe	Nonsense
HB16	Chinese	2	GLA	c.159_160DelAG	p.E54Vfs*7	Reported	Moderate	Frameshift

HB, Haemophilia B.