def load_chromosome_metadata(conn, chrom):
  """Load chromosome metadata

  :param conn:   connection object
  :param chrom:  chromosome number
  :returns chrom, seq_id, seq_len, seq_md5
  """
  c = conn.cursor()
  c.execute("SELECT chrom, seq_id, seq_len, seq_md5 FROM chrom_metadata WHERE chrom=?", (chrom,))
  row = next(c, None)
  return row