生信算法8 - HGVS转换与氨基酸字母表

HGVS 概念

HGVS 人类基因组变异协会(Human Genome Variation Society)提出的转录本编号，cDNA 参考序列(以前缀“c.”表示)、氨基酸参考序列(以前缀“p.”表示)。cDNA 中一种碱基被另一种碱基取代，以“>”进行表示，如：c.2186A>G，表示与参考序列相比，在第 2186 位置的腺嘌呤(A)被鸟嘌呤(G)所取代；在氨基酸中 p.Asp729Gly，表示在第 729 位置的 Asp(天冬氨酸)被 Gly(甘氨酸)取代。

氨基酸字母与缩写转换表

python3.9实现算法。

# 氨基酸缩写与全称转换字典
dict_AA = {'A': {'Abbreviation': 'Ala', 'CN': '丙氨酸', 'EN': 'Alanine'}, 
           'F': {'Abbreviation': 'Phe', 'CN': '苯丙氨酸', 'EN': 'Phenylalanine'}, 
           'C': {'Abbreviation': 'Cys', 'CN': '半胱氨酸', 'EN': 'Cysteine'}, 
           'U': {'Abbreviation': 'Sec', 'CN': '硒半胱氨酸', 'EN': 'Selenocysteine'}, 
           'D': {'Abbreviation': 'Asp', 'CN': '天冬氨酸', 'EN': 'Aspartic acid / Aspartate'}, 
           'N': {'Abbreviation': 'Asn', 'CN': '天冬酰胺', 'EN': 'Asparagine'}, 
           'E': {'Abbreviation': 'Glu', 'CN': '谷氨酸', 'EN': 'Glutamic acid / Glutamate'}, 
           'Q': {'Abbreviation': 'Gln', 'CN': '谷氨酰胺', 'EN': 'Glutamine'}, 
           'G': {'Abbreviation': 'Gly', 'CN': '甘氨酸', 'EN': 'Glycine'}, 
           'H': {'Abbreviation': 'His', 'CN': '组氨酸', 'EN': 'Histidine'}, 
           'L': {'Abbreviation': 'Leu', 'CN': '亮氨酸', 'EN': 'Leucine'}, 
           'I': {'Abbreviation': 'Ile', 'CN': '异亮氨酸', 'EN': 'Isoleucine'},
            'K': {'Abbreviation': 'Lys', 'CN': '赖氨酸', 'EN': 'Lysine'},    
           'O': {'Abbreviation': 'Pyl', 'CN': '吡咯赖氨酸', 'EN': 'Pyrrolysine'}, 
           'M': {'Abbreviation': 'Met', 'CN': '蛋氨酸', 'EN': 'Methionine'}, 
           'P': {'Abbreviation': 'Pro', 'CN': '脯氨酸', 'EN': 'Proline'}, 
           'R': {'Abbreviation': 'Arg', 'CN': '精氨酸', 'EN': 'Arginine'}, 
            'S': {'Abbreviation': 'Ser', 'CN': '丝氨酸', 'EN': 'Serine'}, 
           'T': {'Abbreviation': 'Thr', 'CN': '苏氨酸', 'EN': 'Threonine'}, 
           'V': {'Abbreviation': 'Val', 'CN': '缬氨酸', 'EN': 'Valine'}, 
           'W': {'Abbreviation': 'Trp', 'CN': '色氨酸', 'EN': 'Tryptophan'}, 
           'Y': {'Abbreviation': 'Tyr', 'CN': '酪氨酸', 'EN': 'Tyrosine'}, 
}

# 写入文本
with open("AA_convert.txt", 'w') as fw:
    fw.write("Letter\tAbbreviation\tCN\tEN\n")
    for letter, abbr in dict_AA.items():
        print(letter, ':', abbr)
        line = "{0}\t{1}\t{2}\t{3}\n".format(letter, 
                                             abbr.get('Abbreviation', 'ERROR'),
                                             abbr.get('CN', 'ERROR'), 
                                             abbr.get('EN', 'ERROR'))
        fw.write(line)

# 从文本读取为字典
dict_AA = {}
with open("AA_convert.txt", 'r') as fr:
    # 遍历每行
    for line in fr.readlines():
        # 跳过首行
        if line.startswith('Letter'):
            continue
        line = line.strip().split('\t')
        dict_AA[line[0]] = {'Abbreviation': line[1], 'CN': line[2], 'EN': line[3]}

# 打印字典
print(dict_AA)

打印字典

打印全部氨基酸字母表

# 打印全部氨基酸字母表，用于后续re模块正则表达式
s = ''
for letter, abbr in dict_AA.items():
    if letter != 'Y':
        s += f"{letter}|"
    else:
        s += f"{letter}"
print(s)
#A|F|C|U|D|N|E|Q|G|H|L|I|K|O|M|P|R|S|T|V|W|Y

HGVS写法转换

# 对HGVS写法进行转换
# ANNOVAR注释写法
# SLC25A13:NM_014251:exon1:c.T2C:p.M1T

# 转换后写法
# c.2T>C/p.Met1Thr (NM_014251.3) Exon1/18

import re

def convert_HGVS(hgvs: str, total_exon: int):
    """
    hgvs: 待转换HGVS
    total_exon: 基因的全部外显子数量
    """
    # 按:符号分割输入hgvs
    list_hgvs = hgvs.split(':')

    gene = list_hgvs[0]
    exon = nm = cds_change = aa_change = exon_change_position = aa_change_position = ref = alt = ref_aa = alt_aa = ''
    for context in list_hgvs[1:]:
        if 'exon' in context:
            exon = context
        if 'NM' in context:
            nm = context
        elif 'c.' in context:
            cds_change = context
            
            # 匹配ref碱基、外显子发生变异的坐标和alt碱基
            match = re.search(r'([A|T|C|G]*)(\d+)([A|T|C|G]*)', cds_change)
            if match:
                # 获取ref碱基
                ref = match.group(1)
                # 获取位置
                exon_change_position = match.group(2)
                # 获取alt碱基
                alt = match.group(3)
            else:
                raise Exception("ERROR!")
                
        elif 'p.' in context:
            aa_change = context
            # 匹配ref氨基酸、外显子发生变异对应氨基酸改变的坐标和alt氨基酸
            match = re.search(r'([A|F|C|U|D|N|E|Q|G|H|L|I|K|O|M|P|R|S|T|V|W|Y]*)(\d+)([A|F|C|U|D|N|E|Q|G|H|L|I|K|O|M|P|R|S|T|V|W|Y]*)', aa_change)
            if match:
                # 获取ref氨基酸
                ref_aa = match.group(1)
                # 氨基酸改变的坐标
                aa_change_position = match.group(2)
                # 获取alt氨基酸
                alt_aa = match.group(3)

                # 将字典简写氨基酸转换为三字母缩写氨基酸
                ref_aa = dict_AA[ref_aa].get('Abbreviation', "ERROR")
                alt_aa = dict_AA[alt_aa].get('Abbreviation', "ERROR")
            else:
                raise Exception("ERROR!")
    
    # 调整写法 c.2T>C/p.Met1? (NM_014251.3) Exon1/18
    hgvs_formated = 'c.{exon_change_position}{ref}>{alt}/p.{ref_aa}{aa_change_position}{alt_aa} ({nm}) {exon}/{total_exon}'.format(exon_change_position=exon_change_position,
                                                                                                       ref=ref,
                                                                                                       alt=alt,
                                                                                                       ref_aa=ref_aa,
                                                                                                       aa_change_position=aa_change_position,
                                                                                                       alt_aa=alt_aa,
                                                                                                        nm=nm,
                                                                                                        exon= exon.capitalize(),
                                                                                                        total_exon=total_exon)
    # 打印中间变量
    print(gene, exon, cds_change, aa_change, exon_change_position, ref, alt, aa_change_position, ref_aa, alt_aa)
    return hgvs_formated 

# 测试
print(convert_HGVS(hgvs='SLC25A13:NM_014251:exon1:c.T2C:p.M1T', total_exon=18))
# c.2T>C/p.Met1Thr (NM_014251) Exon1/18

print(convert_HGVS(hgvs='PKD1:NM_001009944:exon15:c.G3496A:p.G1166S', total_exon=46))
# c.3496G>A/p.Gly1166Ser (NM_001009944) Exon15/46